Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2015	Mar. 03, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Trading Symbol	BIOC
Entity Registrant Name	BIOCEPT INC
Entity Central Index Key	0001044378
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		19,683,402
Entity Public Float			$ 44,043,557

Balance Sheets - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 8,821,329	$ 5,364,582
Accounts receivable	34,200	10,600
Inventories, net	349,271	188,728
Prepaid expenses and other current assets	435,938	338,721
Total current assets	9,640,738	5,902,631
Fixed assets, net	946,180	662,422
Total assets	10,586,918	6,565,053
Current liabilities:
Accounts payable	632,538	641,406
Accrued liabilities	966,899	699,903
Supplier financings	42,369	33,674
Current portion of equipment financings	110,924	55,800
Current portion of credit facility	1,588,058
Total current liabilities	3,340,788	1,430,783
Non-current portion of equipment financings, net	291,189	68,801
Non-current portion of credit facility, net	2,638,487	4,731,322
Non-current portion of interest payable	153,547	54,537
Non-current portion of deferred rent	470,172	500,179
Total liabilities	$ 6,894,183	$ 6,785,622
Commitments and contingencies (see Note 19)
Shareholders’ equity/(deficit):
Common stock, $0.0001 par value, 40,000,000 authorized; 4,449,603 issued and outstanding at December 31, 2014; 19,670,054 issued and outstanding at December 31, 2015 (see Note 4)	$ 1,967	$ 445
Additional paid-in capital	158,927,316	138,066,008
Accumulated deficit	(155,236,548)	(138,287,022)
Total shareholders’ equity/(deficit)	3,692,735	(220,569)
Total liabilities and shareholders’ equity/(deficit)	$ 10,586,918	$ 6,565,053

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	19,670,054	4,449,603
Common stock, shares outstanding	19,670,054	4,449,603

Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenues:	$ 609,909	$ 133,415
Costs and expenses:
Cost of revenues	4,596,158	2,170,548
Research and development expenses	2,857,770	4,497,790
General and administrative expenses	5,686,398	5,201,997
Sales and marketing expenses	3,880,386	2,137,004
Total costs and expenses	17,020,712	14,007,339
Loss from operations	(16,410,803)	(13,873,924)
Other income/(expense):
Interest expense, net	(640,478)	(1,789,680)
Change in fair value of warrant liability	931	(200,936)
Other income	102,432
Total other income/(expense):	(537,115)	(1,990,616)
Loss before income taxes	(16,947,918)	(15,864,540)
Income tax expense	(1,608)	(1,506)
Net loss & comprehensive loss	$ (16,949,526)	$ (15,866,046)
Weighted-average shares outstanding used in computing net loss per share attributable to common shareholders:
Basic	16,538,963	3,997,797
Diluted	16,538,963	3,997,797
Net loss per common share:
Basic	$ (1.02)	$ (3.97)
Diluted	$ (1.02)	$ (3.97)

Statements of Shareholders' Equity/(Deficit) - USD ($)	Total	Series A Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2013	$ (12,456,014)	$ 6,942	$ 19	$ 109,958,001	$ (122,420,976)
Beginning balance, shares at Dec. 31, 2013		69,421,047	185,550
Net loss	(5,127,871)
Ending balance at Mar. 31, 2014	9,356,778
Beginning balance at Dec. 31, 2013	(12,456,014)	$ 6,942	$ 19	109,958,001	(122,420,976)
Beginning balance, shares at Dec. 31, 2013		69,421,047	185,550
Stock-based compensation expense	1,822,661			1,822,661
Shares issued for conversion of Series A Preferred Stock		$ (6,942)	$ 165	6,777
Shares issued for conversion of Series A Preferred Stock, shares		(69,421,047)	1,652,851
Shares issued for conversion of notes payable and accrued interest	7,111,999		$ 71	7,111,928
Shares issued for conversion of notes payable and accrued interest, shares			711,202
Reclassification of warrant liability derivative due to triggering event	2,475,620			2,475,620
Shares issued for initial public offering	16,458,104		$ 190	16,457,914
Shares issued for initial public offering, shares			1,900,000
Common stock warrants issued in connection with credit facility	233,107			233,107
Net loss	(15,866,046)				(15,866,046)
Ending balance at Dec. 31, 2014	(220,569)		$ 445	138,066,008	(138,287,022)
Ending balance, shares at Dec. 31, 2014			4,449,603
Beginning balance at Mar. 31, 2014	9,356,778
Net loss	(2,996,840)
Ending balance at Jun. 30, 2014	6,855,762
Net loss	(3,859,794)
Ending balance at Sep. 30, 2014	3,319,532
Net loss	(3,881,541)
Ending balance at Dec. 31, 2014	(220,569)		$ 445	138,066,008	(138,287,022)
Ending balance, shares at Dec. 31, 2014			4,449,603
Net loss	(3,800,728)
Ending balance at Mar. 31, 2015	13,582,795
Beginning balance at Dec. 31, 2014	(220,569)		$ 445	138,066,008	(138,287,022)
Beginning balance, shares at Dec. 31, 2014			4,449,603
Stock-based compensation expense	1,377,824			1,377,824
Shares issued for initial public offering	8,766,946		$ 800	8,766,146
Shares issued for initial public offering, shares			8,000,000
Shares issued for restricted stock units			$ 17	(17)
Shares issued for restricted stock units, shares			174,002
Shares issued pursuant to stock purchase agreement	958,000		$ 79	957,921
Shares issued pursuant to stock purchase agreement, shares			790,000
Exercise of common stock warrants	9,760,060		$ 626	9,759,434
Exercise of common stock warrants, shares			6,256,449
Net loss	(16,949,526)				(16,949,526)
Ending balance at Dec. 31, 2015	3,692,735		$ 1,967	158,927,316	(155,236,548)
Ending balance, shares at Dec. 31, 2015			19,670,054
Beginning balance at Mar. 31, 2015	13,582,795
Net loss	(4,035,105)
Ending balance at Jun. 30, 2015	11,049,961
Net loss	(4,496,193)
Ending balance at Sep. 30, 2015	6,928,277
Net loss	(4,617,500)
Ending balance at Dec. 31, 2015	$ 3,692,735		$ 1,967	$ 158,927,316	$ (155,236,548)
Ending balance, shares at Dec. 31, 2015			19,670,054

Statements of Cash Flows - USD ($)	12 Months Ended
Statements of Cash Flows - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Cash Flows From Operating Activities
Net loss	$ (16,949,526)	$ (15,866,046)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	261,409	251,203
Inventory reserve	(34,437)	(13,779)
Stock-based compensation	1,377,824	1,822,661
Non-cash interest expense related to convertible debt, credit facility and other financing activities	120,663	1,445,068
Change in fair value of warrant liability	(931)	200,936
Increase/(decrease) in cash resulting from changes in:
Accounts receivable	(23,600)	(1,400)
Inventory	(126,106)	(82,126)
Prepaid expenses and other current assets	(80,432)	(401,355)
Other non-current assets		500
Accounts payable	(51,790)	(981,869)
Accrued liabilities	240,901	(1,046,559)
Accrued interest	110,021	58,936
Deferred rent	1,163	38,178
Net cash used in operating activities	(15,154,841)	(14,575,652)
Cash Flows From Investing Activities:
Purchases of fixed assets	(165,160)	(394,925)
Net cash used in investing activities	(165,160)	(394,925)
Cash Flows From Financing Activities:
Net proceeds from issuance of common stock	9,788,057	17,390,240
Proceeds from exercise of common stock warrants	9,760,060
Payments on equipment financings	(74,697)	(23,250)
Payments on supplier and other third party financings	(71,232)	(192,511)
Payments on line of credit	(625,440)	(2,346,000)
Proceeds from borrowings on line of credit		365,000
Proceeds from issuance of convertible notes and warrants		175,000
Net proceeds from borrowings on credit facility and warrants		4,897,502
Net cash provided by financing activities	18,776,748	20,265,981
Net increase in Cash and Cash Equivalents	3,456,747	5,295,404
Cash and Cash Equivalents at Beginning of Period	5,364,582	69,178
Cash and Cash Equivalents at End of Period	8,821,329	5,364,582
Cash paid during the period for:
Interest	405,715	402,075
Taxes	$ 2,184	$ 800

Statements of Cash Flows (Parenthetical) - USD ($)		12 Months Ended
Statements of Cash Flows (Parenthetical) - USD ($)	Feb. 10, 2014	Dec. 31, 2015	Dec. 31, 2014
Financed insurance premium through third party financing		$ 79,896	$ 62,774
Cancellation of insurance premiums amount, other			44,559
Cancellation of insurance premiums partial amount received			10,955
Fair value of common stock warrants issued in conjunction with guarantees on additional borrowings			$ 135,222
Series A Preferred Stock, shares converted to common stock	69,421,047
Common stock, shares issued upon conversion of Series A Preferred Stock	1,652,851
Overallotment issued to underwriter to purchase common stock, period	45 days	45 days
Purchase of common stock by underwriters to cover overallotments, number of shares	285,000		285,000
Purchase of common stock by underwriters to cover overallotments, per share	$ 9.30	$ 1.25
Purchase of common stock by underwriters to cover overallotments, grant date fair value		$ 7,690,395
Exercise price of warrants	$ 10.00	$ 1.56
Warrants to purchase common stock, period	5 years	5 years
Issuance of warrants to purchase shares of common stock, grant date fair value		$ 1,627,396
Underwriter IPO costs	$ 279,760
Underwriter discount from initial public offering	1,330,000
Debt, principal amount converted			$ 6,600,000
Warrants reclassified to additional paid-in capital	2,500,000
Deferred offering costs classified to additional paid in capital	932,136
Common shares issuable to underwriters under granted option		1,200,000
Common Shares issuable to underwriters under warrants granted		1,200,000
Common stock, par value		$ 0.0001	$ 0.0001
Offering costs recorded in prepaid expenses and other current assets reclassified to common stock issuance costs		$ 63,111
Purchases of fixed assets		64,300	$ 19,546
Fixed assets purchased under capital lease obligations		$ 337,085	140,267
Cost related to IPO issuance			63,111
April 2014 Credit Facility [Member]
Warrants to purchase common stock, period		10 years
Issuance of warrants to purchase shares of common stock, grant date fair value			233,107
Aegis Capital Corp [Member]
Purchase of common stock by underwriters to cover overallotments, grant date fair value	$ 202,143		202,143
Issuance of warrants to purchase shares of common stock	95,000	8,000,000
Exercise price of warrants	$ 12.50
Issuance of warrants to purchase shares of common stock, grant date fair value	$ 544,116		$ 544,116
2008 Convertible Note [Member]
Debt, principal amount converted	$ 1,400,000
Conversion price of notes	$ 10.00
Convertible Note converted into preferred/common stock	163,399
2013 Convertible Bridge Notes [Member]
Exercise price of warrants	$ 10.00
Debt, principal amount converted	$ 5,165,000
Accrued interest on convertible debt converted	$ 313,017
Conversion price of notes	$ 10.00
Convertible Note converted into preferred/common stock	547,803
Warrants reclassified to additional paid-in capital	258,249
Convertible Bridge Notes And Line Of Credit [Member]
Exercise price of warrants	$ 10.00
Warrants reclassified to additional paid-in capital	$ 2,475,620
Warrants reclassified to additional paid-in capital	387,152
Common Stock [Member]
Convertible Note converted into preferred/common stock	433,883
Common Stock [Member] \| 2008 Convertible Note [Member]
Convertible Note converted into preferred/common stock	163,399
Accrued interest [Member]
Accrued interest on convertible debt converted	$ 233,982
Accrued interest [Member] \| 2008 Convertible Note [Member]
Accrued interest on convertible debt converted	233,982
Accrued interest [Member] \| 2013 Convertible Bridge Notes [Member]
Accrued interest on convertible debt converted	$ 313,017

The Company and Business Activities	12 Months Ended
The Company and Business Activities	Dec. 31, 2015
Accounting Policies [Abstract]
The Company and Business Activities	1. The Company and Business Activities Biocept, Inc., or the Company, was founded in California in May 1997 and is a commercial-stage cancer diagnostics company developing and commercializing proprietary circulating tumor cell, or CTC, and circulating tumor DNA, or ctDNA, assays utilizing a standard blood sample to improve the treatment that oncologists provide to their patients by providing better, more detailed information on the characteristics of their tumor. The Company operates a clinical laboratory that is CLIA-certified (under the Clinical Laboratory Improvement Amendment of 1988) and CAP-accredited (by the College of American Pathologists), and manufactures cell enrichment and extraction microfluidic channels, related equipment and certain reagents to perform the Company’s diagnostic assays in a facility located in San Diego, California. CLIA certification and accreditation are required before any clinical laboratory may perform testing on human specimens for the purpose of obtaining information for the diagnosis, prevention, treatment of disease, or assessment of health. The assays the Company offers are classified as laboratory developed tests under the CLIA regulations. In July 2013, the Company effected a reincorporation to Delaware by merging itself with and into Biocept, Inc., a Delaware corporation, which had been formed to be and was a wholly-owned subsidiary of the Company since July 23, 2013.

Liquidity and Going Concern Uncertainty	12 Months Ended
Liquidity and Going Concern Uncertainty	Dec. 31, 2015
Accounting Policies [Abstract]
Liquidity and Going Concern Uncertainty	2. Liquidity & Going Concern Uncertainty As of December 31, 2015, cash and cash equivalents totaled $8.8 million. At December 31, 2014 and 2015, the Company had accumulated deficits of $138.3 million and $155.2 million, respectively. For the years ended December 31, 2014 and 2015, the Company incurred net losses of $15.9 million and $16.9 million, respectively. The Company borrowed a total of $0.5 million during the year ended December 31, 2014 under note agreements with certain shareholders and a line of credit. In addition, the Company borrowed $5.0 million during the year ended December 31, 2014 under the April 2014 Credit Facility. At December 31, 2015, the Company had aggregate gross interest-bearing indebtedness of approximately $5.6 million, of which approximately $2.1 million was due within one year in the absence of subjective acceleration of the April 2014 Credit Facility by Oxford Finance LLC, in addition to approximately $1.6 million of accounts payable and accrued liabilities. In February 2016, the Company signed a firm, noncancelable, and unconditional commitment in an aggregate amount of $1,062,500 with a vendor to purchase certain inventory items, payable in quarterly installments of $62,500 through May 2020 (see Note 19 for a description of the Company’s aggregate commitments and contingencies). These factors raise substantial doubt about the Company’s ability to continue as a going concern. The accompanying financial statements have been prepared assuming that the Company will continue as a going concern. The financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the possible inability of the Company to continue as a going concern. While the Company is currently in the commercialization stage of operations, the Company has not yet achieved profitability and anticipates that it will continue to incur net losses in the foreseeable future. Historically, the Company’s principal sources of cash have included proceeds from the issuance of common and preferred stock, proceeds from the exercise of warrants to purchase common stock, proceeds from the issuance of debt, and revenues from clinical laboratory testing through contracted partners. The Company’s principal uses of cash have included cash used in operations, payments relating to purchases of property and equipment and repayments of borrowings. The Company expects that the principal uses of cash in the future will be for continuing operations, hiring of sales and marketing personnel and increased sales and marketing activities, funding of research and development, capital expenditures, and general working capital requirements. The Company expects that, as revenues grow, sales and marketing and research and development expenses will continue to grow, albeit at a slower rate and, as a result, the Company will need to generate significant net revenues to achieve and sustain income from operations. On February 13, 2015, the Company received net cash proceeds of $9.1 million as a result of the closing of a follow-on public offering, before deducting $0.3 million of additional non-underwriting costs incurred. Subsequent to the closing of the follow-on public offering on February 13, 2015 and through March 3, 2016, additional cash proceeds of $9.8 million have been received from the exercise of warrants sold in such offering. On December 21, 2015, the Company received net cash proceeds of $958,000 as a result of a common stock purchase agreement with Aspire Capital Fund, LL, or Aspire Capital, with approximately $14.0 million, or up to 2,984,122 shares, available to be issued to Aspire Capital under this agreement as of March 3, 2016. In May 2015, the SEC declared effective a shelf registration statement filed by the Company. The shelf registration statement allows the Company to issue any combination of its common stock, preferred stock, debt securities and warrants from time to time for an aggregate initial offering price of up to $50 million, subject to certain limitations for so long as the Company’s public float is less than $75 million. As of December 31, 2015, the Company had not sold any securities under this shelf registration statement. The specific terms of future offerings, if any, under this shelf registration statement would be established at the time of such offerings. Management’s Plan to Continue as a Going Concern In order to continue as a going concern, the Company will need, among other things, additional capital resources. Until the Company can generate significant cash from operations, including assay revenues, management’s plans to obtain such resources for the Company include proceeds from offerings of the Company’s equity securities or debt, or transactions involving product development, technology licensing or collaboration. Management can provide no assurances that any sources of a sufficient amount of financing will be available to the Company on favorable terms, if at all.

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Basis of Presentation The financial statements and accompanying notes are prepared in accordance with accounting principles generally accepted in the United States of America. Certain prior period amounts have been reclassified to conform to the current period presentation. Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates these estimates and judgments, including those related to inventories, long-lived assets, convertible debt, derivative liabilities, income taxes, and stock-based compensation. The Company bases its estimates on various assumptions that it believes are reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions. Revenue Recognition Revenue is recognized in accordance with the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, 605, Revenue Recognition, and ASC 954-605 Health Care Entities, Revenue Recognition which requires that four basic criteria must be met before revenue can be recognized: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred and title and the risks and rewards of ownership have been transferred to the client or services have been rendered; (3) the price is fixed or determinable; and (4) collectability is reasonably assured. For contract partners, revenue is recorded based upon the contractually agreed upon fee schedule. When assessing collectability, the Company considers whether there is sufficient payment history to reliably estimate a payor’s individual payment patterns. For new tests where there is limited evidence of payment history at the time the tests are completed, the Company recognizes revenue equal to the amount of cash received until such time as reimbursement experience can be established. Approximately 10% and 34% of the Company’s revenues for the years ended December 31, 2015 and 2014, respectively, results from agreements with contracted partners. This revenue is derived from clinical laboratory testing performed in the Company’s laboratories under agreements with such partners. As there is a contractually agreed upon price, and collectability from the partners is reasonably assured, revenues for these tests are recognized at the time the test is completed. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents. The Company places its cash and cash equivalents with reputable financial institutions that are insured by the Federal Deposit Insurance Corporation (FDIC). At times, deposits held may exceed the amount of insurance provided by the FDIC. The Company has not experienced any losses in its cash and cash equivalents and believes they are not exposed to any significant credit risk. Fair Value Measurement The Company uses a three-tier fair value hierarchy to prioritize the inputs used in the Company’s fair value measurements. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets for identical assets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. The Company believes the carrying amount of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate their estimated fair values due to the short-term maturities of these financial instruments. See Note 5 for further details about the inputs and assumptions used to determine fair value measurements. Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of temporary cash investments. The Company has not experienced losses in such accounts. Management believes that the Company is not exposed to any significant credit risk with respect to its cash and cash equivalents. In 2013, the Company entered into a research support agreement with a not-for-profit tax-exempt organization, Dana-Farber Partners Cancer Care, Inc., or Dana-Farber. For the year ended December 31, 2014, 32% of the revenues earned were billed through this relationship. In addition, 72% of the receivables were due from Dana-Farber at December 31, 2014. In 2014, the Company entered into a research support agreement with a not-for-profit tax-exempt organization, The University of Texas MD Anderson Cancer Center, or MD Anderson. For the years ended December 31, 2014 and 2015, 2% and 5%, respectively, of the revenues earned were billed through this relationship. In addition, 28% and 86% of the receivables were due from MD Anderson at December 31, 2014 and 2015, respectively. Concentrations of credit risk with respect to revenues and accounts receivable are primarily limited to certain clients including Dana-Farber and MD Anderson, and geographies to which the Company provides a significant volume of its services, and to specific payors of our services such as Medicare and individual insurance companies. Approximately 48% of commercial accessions billed from January 1, 2015 through December 31, 2015 were subject to Medicare reimbursement, and approximately 47% and 42% of commercial revenues and total revenues, respectively, during the twelve months ended December 31, 2015 were associated with Medicare. The Company’s client base consists of a large number of geographically dispersed clients diversified across various customer types. For the year ended December 31, 2014, revenues derived from clients within the states of Texas, Massachusetts, and California accounted for approximately 34%, 32% and 15%, respectively, of total revenues. For the year ended December 31, 2015, revenues derived from clients within the states of Texas, California and Maryland accounted for approximately 32%, 18%, and 12%, respectively, of total revenues. For the year ended December 31, 2014, the first, second, and third most significant clients accounted for approximately 32%, 20%, and 6%, respectively, of total revenues. For the year ended December 31, 2015, the first, second, and third most significant clients accounted for approximately 12%, 9%, and 5%, respectively, of total revenues. The Company operates in one reportable business segment and historically has derived revenues only from the United States, with international revenues of $16,027, or approximately 3% of our net revenues, commencing in 2015 and received through the twelve months ended December 31 of such year. Certain components used in the Company’s current or planned products are available from only one supplier, and substitutes for these components cannot be obtained easily or would require substantial design or manufacturing modifications or identification and qualification of alternative sources. Accounts Receivable Accounts receivable are carried at original invoice amounts, less an estimate for doubtful receivables, based on a review of all outstanding amounts on a periodic basis. The estimate for doubtful receivables is determined from an analysis of the accounts receivable on a quarterly basis, and is recorded as bad debt expense. As the Company only recognizes revenue to the extent collection is expected and reasonably assured, bad debt expense related to receivables from patient service revenue is recorded in general and administrative expense in the statement of operations and comprehensive loss. Accounts receivable are written off when deemed uncollectible. Recoveries of accounts receivable previously written off are recorded when received. As of December 31, 2014 and 2015, management determined that all of the amounts recorded as accounts receivable were collectible, and no allowance for doubtful accounts was needed. Inventories Inventories are valued at the lower of cost or market value. Cost is determined by the average cost method. The Company records adjustments to its inventory for estimated obsolescence or diminution in market value equal to the difference between the cost of the inventory and the estimated market value. At the point of loss recognition, a new cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. In addition, the Company records a liability for firm, noncancelable, and unconditional purchase commitments with contract manufacturers and suppliers for quantities in excess of the Company’s future demand forecasts consistent with its valuation of excess and obsolete inventory. Fixed Assets Fixed assets consist of machinery and equipment, furniture and fixtures, computer equipment and software, leasehold improvements, capital leased equipment and construction in process. Fixed assets are stated at cost less accumulated depreciation and amortization. Additions, improvements, and major renewals are capitalized. Maintenance, repairs, and minor renewals are expensed as incurred. Depreciation is determined using the straight-line method over the estimated useful lives of the assets, which range from three to five years. Leasehold improvements are amortized over the life of the lease or the asset, whichever is shorter. Depreciation expense for the years ended December 31, 2014 and 2015 was approximately $251,000 and $261,000, respectively. Upon sale, retirement or disposal of fixed assets, the accounts are relieved of the cost and the related accumulated depreciation or amortization with any gain or loss recorded to the statement of operations. Fixed assets are reviewed for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable. These computations utilize judgments and assumptions inherent in the estimates of future cash flows to determine recoverability of these assets. If the assumptions about these assets were to change as a result of events or circumstances, the Company may be required to record an impairment loss. Warrant Liability Warrants for shares that are contingently redeemable and for which the exercise price is not fixed are classified as liabilities on the accompanying balance sheets and carried at their estimated fair value, determined through use of a Black-Scholes valuation model. As of and for the years ended December 31, 2014 and 2015, the Company evaluated and concluded that the fair value obtained from the Black-Scholes method of valuing the warrant liability does not materially differ from the valuation of such warrants using the Monte Carlo or binomial lattice simulation models, and therefore the use of the Black-Scholes valuation model was considered a reasonable method to value the warrants. At the end of each reporting period, any changes in fair value are recorded as a component of other income (expense). As of the closing of the Company’s IPO on February 10, 2014, the exercise price underlying the majority of the Company’s outstanding warrants was fixed and the fair value of those warrants was reclassified to shareholders’ equity/(deficit), while a preferred stock warrant to purchase an equivalent of 1,587 shares of common stock remained liability-classified at December 31, 2015. Stock-based Compensation The Company accounts for stock-based compensation under the provisions of FASB ASC Topic 718, Compensation—Stock Compensation, which requires the measurement and recognition of compensation expense for all stock-based awards made to employees and directors based on estimated fair values on the grant date. The Company estimates the fair value of stock option awards on the date of grant using the Black-Scholes option pricing model, while the fair value of restricted stock unit awards, or RSUs, is determined by the Company’s stock price on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods using the straight-line method. The Company estimates forfeitures at the time of grant and revises these estimates in subsequent periods if actual forfeitures differ from those estimates (see Note 12). The Company accounts for stock-based compensation awards to non-employees in accordance with FASB ASC Topic 505-50, Equity-Based Payments to Non-Employees, or ASC 505-50. Under ASC 505-50, the Company determines the fair value of the warrants or stock-based compensation awards granted as either the fair value of the consideration received or the fair value of the equity instruments issued, whichever is more reliably measurable. All issuances of equity instruments issued to non-employees as consideration for goods or services received by the Company are accounted for based on the fair value of the equity instruments issued. These awards are recorded in expense and additional paid-in capital in shareholders’ equity over the applicable service periods based on the fair value of the options at the end of each period. Calculating the fair value of stock-based awards requires the input of highly subjective assumptions into the Black-Scholes valuation model. Stock-based compensation expense is calculated using the Company’s best estimates, which involves inherent uncertainties, and the application of management’s judgment. Significant estimates include the fair value of the Company’s common stock at the date of grant for awards granted prior to its IPO, the expected life of the stock option, stock price volatility, risk-free interest rate and forfeiture rate. Research and Development Research and development costs are expensed as incurred. The amounts expensed in the years ended December 31, 2014 and 2015 were approximately $4,498,000 and $2,858,000, respectively, which includes salaries of research and development personnel. Income Taxes The Company provides for income taxes utilizing the liability method. Under the liability method, current income tax expense or benefit is the amount of income taxes expected to be payable or refundable for the current year. A deferred income tax asset or liability is computed for the expected future impact of differences between the financial reporting and tax bases of assets and liabilities and for the expected future tax benefit to be derived from tax credits. Tax rate changes are reflected in the computation of the income tax provision during the period such changes are enacted. Deferred tax assets are reduced by a valuation allowance when, in management’s opinion, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. The Company’s valuation allowance is based on available evidence, including its current year operating loss, evaluation of positive and negative evidence with respect to certain specific deferred tax assets including evaluation sources of future taxable income to support the realization of the deferred tax assets. The Company has established a full valuation allowance on the deferred tax assets as of December 31, 2014 and 2015, and therefore has not recognized any income tax benefit or expense in the periods presented. ASC 740, Income Taxes, or ASC 740, clarifies the accounting for uncertainty in income taxes recognized in the financial statements. ASC 740 provides that a tax benefit from uncertain tax positions may be recognized when it is more-likely-than-not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits of the position. Income tax positions must meet a more-likely-than-not recognition threshold to be recognized. ASC 740 also provides guidance on measurement, derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company recognizes interest and/or penalties related to income tax matters in income tax expense. There is no accrual for interest or penalties for income taxes on the balance sheets at December 31, 2014 and 2015, and the Company has not recognized interest and/or penalties in the statements of operations for the years ended December 31, 2014 and 2015. Recent Accounting Pronouncements In May 2014, the FASB issued authoritative guidance that requires entities to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. This proposed guidance has been deferred and would be effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The Company is currently in the process of evaluating the impact of the adoption of this guidance on its financial statements and disclosures. In June 2014, the FASB issued authoritative guidance requiring share-based payments with a performance target which affects vesting and that could be achieved after the requisite service period be treated as a performance condition. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. The Company does not expect adoption of this guidance to have a material impact on its financial statements or disclosures. In August 2014, the FASB issued authoritative guidance requiring management to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. Certain additional financial statement disclosures are required if such conditions or events are identified. This guidance is effective for the annual reporting period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. The Company is currently in the process of evaluating the impact of the adoption of this guidance on its financial statements and disclosures. In April 2015, the FASB issued authoritative guidance requiring debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability. This guidance is effective on a retrospective basis for the annual reporting period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. The Company early adopted this guidance on a retrospective basis for the interim reporting period ended March 31, 2015. A balance of $23,194 of such costs were reclassified from other non-current assets, net to non-current portion of credit facility, net in the Company’s balance sheet as of December 31, 2014. A total of $12,778 of such costs remain unamortized and recorded as an offset to non-current portion of credit facility, net in the Company’s balance sheet at December 31, 2015. In July 2015, the FASB issued authoritative guidance requiring entities that do not measure inventory using the retail inventory method or on a last-in, first-out basis to record inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. This guidance is effective on a prospective basis for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Company does not expect adoption of this guidance to have a material impact on its financial statements or disclosures. In August 2015, the FASB issued amendments to SEC paragraphs referenced in authoritative guidance around the presentation and subsequent measurement of debt issuance costs associated with line-of-credit arrangements. These amendments state that the SEC staff would not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The Company’s adoption of these amendments upon issuance did not have a material impact on its financial statements or disclosures. In November 2015, the FASB issued authoritative guidance requiring that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and may be applied to all deferred tax assets and liabilities on a retrospective basis for all periods presented. The Company early adopted the provisions of this authoritative guidance for the years ended December 31, 2014 and 2015. The adoption of this guidance did not have a material impact on the Company’s financial statements or disclosures. In January 2016, the FASB issued authoritative guidance requiring, among other things, that certain equity investments be measured at fair value with changes in fair value recognized in net income, that financial assets and financial liabilities be presented separately by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements, that the prior requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet be eliminated, and that a reporting organization is to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. Early adoption of the instrument-specific credit risk amendment is permitted. The Company does not expect adoption of this guidance to have a material impact on its financial statements or disclosures. In February 2016, the FASB issued authoritative guidance requiring, among other things, that entities recognize the assets and liabilities arising from leases on the balance sheet under revised criteria, while the classification criteria for distinguishing between finance leases and operating leases are substantially similar to the classification criteria in the previous leases guidance. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The Company is currently in the process of evaluating the impact of the adoption of this guidance on its financial statements and disclosures.

Sales of Equity Securities	12 Months Ended
Sales of Equity Securities	Dec. 31, 2015
Equity [Abstract]
Sales of Equity Securities	4. Sales of Equity Securities Pursuant to an underwriting agreement dated February 4, 2014 between the Company and Aegis Capital Corp., or Aegis, as representative of the several underwriters named therein, an IPO of 1,900,000 shares of common stock at $10.00 per share was effected on February 5, 2014. The closing of the sale of these shares to the underwriters occurred on February 10, 2014. The Company received, after deducting underwriting discounts and additional costs paid to the underwriters, $17.4 million of net cash proceeds from the sale of these 1,900,000 shares. The total increase in capital as a result of the sale of these shares was $16.5 million after deducting $0.9 million of additional non-underwriter costs incurred that were netted against these proceeds under applicable accounting guidance. Additionally, the underwriters were granted a 45 day option from the closing date of the IPO to purchase up to 285,000 shares of common stock at $9.30 per share to cover overallotments with an estimated grant date fair value of $0.2 million, which was not exercised. In addition, designees of Aegis were issued warrants to buy (in the aggregate) up to 95,000 shares of common stock at $12.50 per share with a term of five years and an estimated grant date fair value of $0.5 million. On February 4, 2014, as contemplated by the registration statement covering the IPO, 69,421,047 shares of outstanding Series A Convertible Preferred Stock with a par value of $0.0001 per share were converted into 1,652,851 shares of common stock and the Company’s certificate of incorporation was amended to provide for an authorized capitalization of 40,000,000 shares of common stock and 5,000,000 shares of preferred stock. There were no shares of preferred stock issued or outstanding as of December 31, 2014 or 2015. In connection with the closing of the IPO on February 10, 2014, (i) the $1.4 million principal amount and $0.2 million of accrued interest related to the convertible note issued in 2008 were converted at $10.00 per share into a total of 163,399 shares of common stock, (ii) the $5.2 million principal amount and $0.3 million of accrued interest related to the convertible notes issued in 2013 were converted at $10.00 per share into a total of 547,803 shares of common stock, (iii) the exercise price of the warrants associated with the convertible notes issued in 2013 was fixed at $10.00 per share for an aggregate 258,249 shares of common stock, (iv) the exercise price of the warrants associated with the $2.6 million of collateral provided to secure the Company’s line of credit was fixed at $10.00 per share for an aggregate 128,903 shares of common stock, (v) 73,151 shares of common stock vested as settlement of certain RSUs (which were previously expressed in shares of preferred stock) and became issuable subsequent to the expiration of the 180 day lock-up period following the IPO, (vi) the Company’s Executive Chairman ceased to be an employee and continues to serve as non-executive Chairman, (vii) the number of shares of common stock covered by the Company’s 2013 Equity Incentive Plan increased by 800,000, (viii) all but 1,587 of the preferred warrants previously outstanding were canceled due to early termination clauses associated with the IPO, (ix) derivative warrant liabilities of $2.5 million associated with the aggregate of 387,152 common stock warrants related to the convertible notes issued in 2013 and line of credit were reclassified to additional paid-in capital when their underlying exercise price was fixed, (x) unamortized discounts of $1.0 million related to the warrants associated with the convertible notes issued in 2013 and line of credit were reclassified to interest expense, and (xi) offering costs associated with the IPO of $0.9 million were reclassified from prepaid expenses and other current assets to additional paid-in capital, while additional underwriter IPO costs and discounts of $0.3 million and $1.3 million, respectively, were netted against the proceeds from the IPO and are reflected as an offset to additional paid-in capital. Subsequent to December 31, 2013, the maximum amount of the Company’s line of credit was increased to approximately $2.6 million and common stock warrants were issued to four shareholders in conjunction with their guarantees on the Company’s additional borrowings under the line of credit. On February 10, 2014, the current outstanding balance under the line of credit of approximately $2.3 million plus accrued interest of $27,043 was paid in full using the net proceeds from the IPO. On February 13, 2014, the Compensation Committee of the Company’s Board of Directors approved payments of approximately $1.0 million for deferred salary obligations, including contractual interest, to current and former executive officers pursuant to previously existing agreements, which was fully disbursed by April 2014 using the net proceeds from the IPO. An additional $344,883 in deferred salary obligations and interest thereon was paid to former employees other than executive officers. Also on February 13, 2014, in connection with the closing of the IPO and pursuant to a director compensation policy adopted by the Company’s Board of Directors in 2013, the Company’s Board of Directors approved annual cash retainers to non-employee directors, and granted 238,500 stock options under the Company’s 2013 Equity Incentive Plan to non-employee directors. These option awards vest in equal annual installments over 3 years from the date of grant with a 10 year term, subject to continuing service requirements. Subsequently in February 2014, the Company’s Board of Directors approved grants of 54,298 stock options as a result of the closing of the IPO pursuant to the terms of underlying employment agreements. Included in the stock options granted pursuant to the terms of underlying employment agreements were 53,108 option awards granted to the Company’s non-executive Chairman, which vested fully on the date of grant. Under the terms of certain employment agreements with executive officers, the Company incurred additional cash compensation expense of $150,000 immediately, and $225,000 annually, upon the closing of its IPO. All payments required under these agreements as a result of the closing of the IPO on February 10, 2014 were subsequently made in February and March 2014, using the net proceeds from the IPO. During the year ended December 31, 2014, the Company repaid in full the remaining amounts outstanding of approximately $70,000 due for laboratory equipment under financing agreements with a supplier, which is a business owned by a member of the Company’s board of directors, using the net proceeds from the IPO. Pursuant to an underwriting agreement dated February 9, 2015 between the Company, Aegis and Feltl and Company, as underwriters named therein, a public offering of 8,000,000 shares of the Company’s common stock and warrants to purchase up to an aggregate of 8,000,000 shares of common stock was effected at a combined offering price of $1.25. The estimated grant date fair value of these warrants of $7.7 million was recorded as an offset to additional paid-in capital within common stock issuance upon the closing of this offering (see Note 5). Each of the members of the Company’s Board of Directors participated in this offering, purchasing an aggregate 142,000 shares of the Company’s common stock and warrants to purchase up to an aggregate of 142,000 shares of its common stock for a total purchase price of $177,500. All warrants sold in this offering have a per share exercise price of $1.56, are exercisable immediately and expire five years from the date of issuance. The closing of the sale of these securities to the underwriters occurred on February 13, 2015, when the Company received, after deducting underwriting discounts and additional costs paid to the underwriters, $9.1 million of net cash proceeds. The total increase in capital as a result of the sale of these shares and warrants was $8.8 million after deducting $0.3 million of additional non-underwriter costs incurred. Additionally, the underwriters were granted a 45-day option to purchase up to 1,200,000 additional shares of common stock at a price of $1.25 per share and/or additional warrants to purchase up to 1,200,000 shares of common stock at a price of $0.0001 per warrant, less underwriting discounts and commissions, to cover over-allotments, if any, which was not exercised. The estimated grant date fair value of the over-allotment options and warrants of $1.6 million was recorded as an offset to additional paid-in capital within common stock issuance costs upon the closing of this offering (see Note 5). Underwriter costs and discounts of $0.2 million and $0.7 million, respectively, as well as additional non-underwriter costs associated with the offering of $0.3 million, were also recorded to common stock issuance costs upon closing. Subsequent to the closing of this offering on February 13, 2015 and through March 3, 2016, additional cash proceeds of $9.8 million have been received from the exercise of warrants sold in such offering. As such, the aggregate total increase in capital related to this offering has been $18.6 million, after deducting $0.9 million of underwriter costs and discounts and $0.3 million of additional non-underwriter costs incurred, which were netted against these proceeds under applicable accounting guidance. On December 21, 2015, the Company entered into a common stock purchase agreement with Aspire Capital, which committed to purchase up to an aggregate of $15.0 million of shares of the Company’s common stock over the 30-month term of the common stock purchase agreement. Upon execution of the common stock purchase agreement, the Company sold to Aspire Capital 625,000 shares of common stock at $1.60 per share for proceeds of $1,000,000, and concurrently also entered into a registration rights agreement with Aspire Capital, pursuant to which the Company filed a registration statement registering the sale of the shares of the Company’s common stock that have been and may be issued to Aspire Capital under the common stock purchase agreement. Under the common stock purchase agreement, on any trading day selected by the Company, the Company has the right, in its sole discretion, to present a purchase notice directing Aspire Capital to purchase up to 100,000 shares of the Company’s common stock per business day, up to $15.0 million of common stock in the aggregate at a per share price equal to the lesser of either i) the lowest sale price of the Company’s common stock on the purchase date, or ii) the arithmetic average of the three lowest closing sale prices for the Company’s common stock during the 10 consecutive trading days ending on the trading day immediately preceding the purchase date. In addition, on any date on which the Company submits a purchase notice to Aspire Capital in an amount equal to 100,000 shares and the Company’s stock price is not less than $0.50 per share, the Company also has the right, in its sole discretion, to present Aspire Capital with a volume-weighted average price purchase notice directing Aspire Capital to purchase an amount of stock equal to up to 30% of the aggregate shares of the Company’s common stock traded on the its principal market on the next trading day, subject to a maximum number of shares the Company may determine. The purchase price per share pursuant to such volume-weighted average price purchase notice is generally 97% of the volume-weighted average price for the Company’s common stock traded on its principal market on the volume-weighted average purchase date. The purchase price will be adjusted for any reorganization, recapitalization, non-cash dividend, stock split, or other similar transaction occurring during the period(s) used to compute the purchase price. The Company may deliver multiple purchase notices and volume-weighted average price purchase notices to Aspire Capital from time to time during the term of the common stock purchase agreement, so long as the most recent purchase has been completed. The common stock purchase agreement provides that the Company and Aspire Capital shall not effect any sales on any purchase date where the closing sale price of the Company’s common stock is less than $0.50. There are no trading volume requirements or restrictions under the common stock purchase agreement, and the Company will control the timing and amount of sales of its common stock to Aspire Capital. Aspire Capital has no right to require any sales by the Company, but is obligated to make purchases from the Company as directed by the Company in accordance with the common stock purchase agreement. There are no limitations on use of proceeds, financial or business covenants, restrictions on future fundings, rights of first refusal, participation rights, penalties or liquidated damages in the common stock purchase agreement. In consideration for entering into, and concurrently with the execution of, the common stock purchase agreement, the Company issued to Aspire Capital 165,000 shares of its common stock. The common stock purchase agreement may be terminated by the Company at any time, at its discretion, without any cost to the Company. Aspire Capital has agreed that neither it nor any of its agents, representatives and affiliates shall engage in any direct or indirect short-selling or hedging of the Company’s common stock during any time prior to the termination of the common stock purchase agreement. Any proceeds the Company receives under the common stock purchase agreement are expected to be used for working capital and general corporate purposes. Costs associated with the offering of $42,000 were also recorded to common stock issuance costs upon closing under applicable accounting guidance, and as such, the aggregate total increase in capital related to this transaction has been $958,000 through March 3, 2016. Approximately $14.0 million, or up to 2,984,122 shares, remains available to be issued to Aspire Capital under this agreement as of March 3, 2016.

Fair Value Measurement

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Fair Value Measurement

5. Fair Value Measurement

Warrant Liability Derivatives

The Company classified the fair value measurements of the Company’s warrant liability derivatives as Level 3 in all periods presented. The Company adjusted the carrying value of the warrants classified as liabilities until the completion of its IPO on February 10, 2014, at which time the exercise price was fixed at $10.00 per share and the fair value of the warrants was reclassified to shareholders’ equity/(deficit), except for a warrant for 1,587 preferred shares that remains outstanding at December 31, 2015 (see Note 4).

As of closing of the Company’s IPO on February 10, 2014, the aggregate common stock warrant liability of approximately $2,476,000 was estimated using a Black-Scholes valuation model with the following assumptions for both the five-year and two-year common stock warrant terms separately:

	Five-year term			Two-year term
Stock price	$	8.91		$	8.91
Exercise price	$	10.00		$	10.00
Expected dividend yield		0.00	%		0.00	%
Discount rate-bond equivalent yield		1.48	%		0.32	%
Expected life (in years)		5.00			2.00
Expected volatility		90.0	%		90.0	%

The following table includes a summary of changes in the fair value of the common and preferred share warrants for the years ended December 31, 2014 and 2015:

	Fair Value Measurements
	at Reporting Date Using
	Significant Unobservable
	Inputs (Level 3)
Balance at December 31, 2013	$	2,140,532
Warrant liability incurred in 2014		135,222
Change in fair value included in expense in 2014		200,936
Warrant liability reclassified to additional paid-in capital in 2014		(2,475,620	)
Balance at December 31, 2014		1,070
Change in fair value included in expense in 2015		(931	)
Balance at December 31, 2015	$	139

The change in the estimated fair value of the total liability outstanding for all outstanding warrants of approximately $(201,000) and $1,000 was recognized as a non-cash gain/(loss) and included in total other income/(expense) in the Company’s statements of operations and comprehensive loss for the years ended December 31, 2014 and 2015, respectively.

Other Fair Value Measurements

In connection with the closing of the Company’s IPO on February 10, 2014, the IPO’s underwriters were granted a 45 day option to purchase up to 285,000 shares of common stock to cover overallotments with a grant date fair value of $202,143, which was not exercised. Additionally, certain designees of the representative of the underwriters were issued warrants to buy (in the aggregate) up to 95,000 shares of common stock with a grant date fair value of $544,116. The fair values of these stock option and common stock warrants were estimated using Black-Scholes valuation models with the following assumptions:

	Over-allotment Options			Warrants
Stock price	$	8.91		$	8.91
Exercise price	$	9.30		$	12.50
Expected dividend yield		0.00	%		0.00	%
Discount rate-bond equivalent yield		0.07	%		1.46	%
Expected life (in years)		0.12			5.00
Expected volatility		70.0	%		90.0	%

In connection with the closing of the Company’s public offering on February 13, 2015, warrants were issued to buy (in the aggregate) up to 8,000,000 shares of common stock with an estimated grant date fair value of $7,690,395, which was recorded as an offset to additional paid-in capital within common stock issuance costs. Also in connection with the closing of the Company’s follow-on public offering on February 13, 2015, the underwriters were granted a 45 day option from the closing date of the offering to purchase up to 1,200,000 additional shares of common stock at a price of $1.25 per share and/or additional warrants to purchase up to 1,200,000 shares of common stock at a price of $0.0001 per warrant, less underwriting discounts and commissions, to cover over-allotments, if any. The estimated aggregate grant date fair value of these over-allotment options and warrants of $1,627,396 was also recorded to common stock issuance costs as a component of additional paid-in capital. The fair values of these over-allotment options and all common stock warrants issued in this offering were estimated using Black-Scholes valuation models with the following assumptions:

	Over-allotment Options			Warrants
Stock price	$	1.41		$	1.41
Exercise price	$	1.25		$	1.56
Expected dividend yield		0.00	%		0.00	%
Discount rate-bond equivalent yield		0.02	%		1.53	%
Expected life (in years)		0.12			5.00
Expected volatility		168.1	%		90.0	%

The estimated grant date fair values of these non-cash equity classified instruments were recorded as an offset to additional paid-in capital within common stock issuance costs.

In connection with the closing of the April 2014 Credit Facility on April 30, 2014, the lender was granted a warrant to purchase 52,966 shares of common stock with a 10 year term and an estimated grant date fair value of $233,107 (see Note 7). The fair value of this warrant was estimated using a Black-Scholes valuation model with the following assumptions:

Stock price	$	4.74
Exercise price	$	4.72
Expected dividend yield		0.00	%
Discount rate-bond equivalent yield		2.67	%
Expected life (in years)		10.00
Expected volatility		110.0	%

The estimated grant date fair value of this non-cash equity classified instrument was recorded as a discount to outstanding debt and is amortized to interest expense utilizing the effective interest method over the underlying term of the loan.

The estimated fair value of the April 2014 Credit Facility at December 31, 2015 approximated carrying value, which was determined using a discounted cash flow analysis. The analysis considered interest rates of instruments with similar maturity dates, which involved the use of significant unobservable Level 3 inputs (see Note 7).

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Balance Sheet Details

12 Months Ended

Dec. 31, 2015

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Balance Sheet Details

6. Balance Sheet Details

The following provides certain balance sheet details:

	December 31,		December 31,
	2014		2015
Fixed Assets
Machinery and equipment	$	2,922,303	$	2,518,158
Furniture and office equipment		209,844		143,726
Computer equipment and software		681,508		577,898
Leasehold improvements		506,328		514,614
Financed equipment		878,447		914,179
Construction in process		72,172		70,815
		5,270,602		4,739,390
Less accumulated depreciation and amortization		4,608,180		3,793,210
Total fixed assets, net	$	662,422	$	946,180
Accrued Liabilities
Accrued interest	$	33,125	$	28,981
Accrued payroll		82,241		128,753
Accrued vacation		276,574		307,845
Accrued bonuses		302,763		376,100
Accrued sales commissions		—		76,574
Warrant liability		1,070		139
Current portion of deferred rent		—		31,170
Other		4,130		17,337
Total accrued liabilities	$	699,903	$	966,899

During the year ended December 31, 2015, fixed assets, with an aggregate gross book value and corresponding accumulated depreciation amount of approximately $1,076,000, were disposed of.

April 2014 Credit Facility	12 Months Ended
April 2014 Credit Facility	Dec. 31, 2015
Debt Disclosure [Abstract]
April 2014 Credit Facility	7. April 2014 Credit Facility On April 30, 2014, the Company received net cash proceeds of approximately $4,898,000 pursuant to the execution of our April 2014 Credit Facility with Oxford Finance LLC. Upon the entry into the April 2014 Credit Facility, the Company was required to pay the lenders a facility fee of $50,000 in conjunction with the funding of the term loan. The April 2014 Credit Facility is secured by substantially all of the Company’s personal property other than its intellectual property. Amounts due to Oxford Finance LLC under the April 2014 Credit Facility are callable before maturity by the lender under certain subjective acceleration clauses of the underlying agreement, including changes deemed to be materially adverse by the lender. The term loan under the April 2014 Credit Facility bears interest at an annual rate equal to the greater of (i) 7.95% or (ii) the sum of (a) the three-month U.S. LIBOR rate reported in the Wall Street Journal three business days prior to the funding date of the term loan, plus (b) 7.71%. The term loan bears interest at an annual rate of 7.95%. The Company was required to make interest-only payments on the term loan through August 1, 2015. The outstanding term loan under the April 2014 Credit Facility began amortizing at the end of the applicable interest-only period, with monthly payments of principal and interest being made by the Company to the lenders in consecutive monthly installments following such interest-only period. The term loan under the April 2014 Credit Facility matures on July 1, 2018. Upon repayment, the Company is also required to make a final payment to the lenders equal to 5.5% of the original principal amount of the term loan funded. At its option, the Company may prepay the outstanding principal balance of the term loan in whole but not in part, subject to a prepayment fee of 2% of the amount prepaid if the prepayment occurs prior to April 30, 2016, and 1% of any amount prepaid after April 30, 2016. The April 2014 Credit Facility includes affirmative and negative covenants applicable to the Company and any subsidiaries created in the future. The affirmative covenants include, among others, covenants requiring the Company to maintain its legal existence and governmental approvals, deliver certain financial reports and maintain insurance coverage. The negative covenants include, among others, restrictions on transferring collateral, incurring additional indebtedness, engaging in mergers or acquisitions, paying dividends or making other distributions, making investments, creating liens, selling assets, and suffering a change in control, in each case subject to certain exceptions. The April 2014 Credit Facility also includes events of default, the occurrence and continuation of which provide Oxford Finance LLC, as collateral agent, with the right to exercise remedies against the Company and the collateral securing the term loan under the April 2014 Credit Facility, including foreclosure against the Company’s properties securing the April 2014 Credit Facility, including its cash. These events of default include, among other things, the Company’s failure to pay any amounts due under the April 2014 Credit Facility, a breach of covenants under the April 2014 Credit Facility, insolvency, a material adverse change, the occurrence of any default under certain other indebtedness in an amount greater than $250,000, and a final judgment against the Company in an amount greater than $250,000. A warrant to purchase up to 52,966 shares of the Company’s common stock at an exercise price of $4.72 per share with a term of 10 years was issued to Oxford Finance LLC on April 30, 2014 (see Note 5). Issuance costs of $102,498 associated with the term loan under the April 2014 Credit Facility were recorded as a discount to outstanding debt as of the closing date, resulting in net proceeds of $4,897,502. The estimated fair value of the warrant issued of $233,107 was recorded as a discount to outstanding debt as of the closing date. The discounts and other issuance costs are amortized to interest expense utilizing the effective interest method over the underlying term of the loan. The total amount of interest expense recorded during the years ended December 31, 2014 and 2015 related to the April 2014 Credit Facility was $380,264 and $611,911, respectively. Approximately $74,000 and $113,000 related to accretion of the discount was recognized as interest expense during the years ended December 31, 2014 and 2015, respectively, with approximately $261,000 and $148,000, respectively, remaining unamortized and reflected as a discount to the debt. The effective annual interest rate associated with the April 2014 Credit Facility was 10.81% at December 31, 2014 and 11.50% at December 31, 2015.

Line of Credit	12 Months Ended
Line of Credit	Dec. 31, 2015
Debt Disclosure [Abstract]
Line of Credit	8. Line of Credit In July 2013, the Company entered into a revolving line of credit with UBS Bank USA in the initial amount of $1.5 million. Interest accrued daily on the outstanding balance and was paid monthly at a variable rate which, as of December 31, 2013, was 2.75% over the 30 day LIBOR rate or a nominal annual interest rate of 2.92%. As of December 31, 2013, the amount outstanding under this revolving line of credit was approximately $2.0 million. Subsequent to December 31, 2013, the maximum amount of the line of credit was increased to approximately $2.6 million. Five of the Company’s affiliated parties guaranteed the loan and pledged financial assets to the bank to secure their guaranties, as approved by the Company’s Board of Directors. In return, the Company issued common stock warrants to the guarantors. The number of shares subject to the common stock warrants was determined by dividing the warrant coverage amount, which is 50% of the fair market value of the collateral provided by the respective guarantors to secure their respective guaranty obligations to the bank, by the exercise price set at the price per share of the Company’s common stock sold in its IPO. See Note 5 for further discussion of the warrant liabilities. The Company entered into an agreement with the guarantors that provided for reimbursement of any amounts paid by them on their guaranties. This reimbursement obligation was secured by a security interest in the Company’s assets. In connection with the closing of the Company’s IPO on February 10, 2014, the current outstanding balance under the line of credit of $2,346,000 plus accrued interest of $27,043 was paid in full, and the exercise price of the warrants associated with the $2,578,104 of collateral provided was fixed at $10.00 per share for an aggregate 128,903 shares of common stock, with associated derivative warrant liabilities of $513,603 reclassified to additional paid-in capital.

Convertible Notes and Warrants	12 Months Ended
Convertible Notes and Warrants	Dec. 31, 2015
Temporary Equity Disclosure [Abstract]
Convertible Notes and Warrants	9. Convertible Notes and Warrants Preferred Shares Goodman Note During April 2005, the Company entered into an unsecured loan agreement for $15,000,000, or the Goodman Note. The note required interest payments and principal settlement upon maturity at the earliest of (a) April 20, 2010, (b) the Company being acquired, or (c) the Company having a change in control, other than through the sale of preferred shares. During January 2009, the Company entered into an amendment and restatement of the unsecured amended loan, whereby the parties agreed that the principal amount would be reduced to $3,000,000. The amended and restated unsecured note accrued interest at a variable rate per annum based on prime plus 25 basis points. 25% of the accrued interest was due and payable quarterly in arrears on the last business day of each three-month quarter beginning February 1, 2009. The remaining 75% of the accrued interest was not to be compounded by becoming part of the principal, and was due and payable in a lump-sum payment on the maturity date. The principal and any interest amounts that remain outstanding was set to mature at the earlier of (a) April 20, 2010, or (b) the date immediately prior to the Company’s closing of an acquisition or asset transfer as defined by the Company’s amended and restated articles of incorporation. In conjunction with the 2009 amendment, the Company issued a warrant to purchase preferred shares issued in the first equity financing to occur subsequent to the execution of the note, and in which the Company receives at least $2,000,000 in gross aggregate proceeds. The exercise price of the warrant would have been equal to the per share price of preferred shares sold in that equity financing, and the number of shares that may have been exercised was equal to 10% of the principal amount of the convertible loan divided by the exercise price. Early termination of the warrant could occur upon an IPO, or if the Company was acquired. The holder of the warrant was to be given 20 days advance notice of such an event, and the warrant would terminate if not exercised before the date of the event. A qualifying equity financing occurred during February 2009, which set the warrant exercise price at $0.60 per share. During May 2010, the Company entered into a second amendment and restatement of the Goodman Note in order to extend the maturity date and amend the timing of payments to be made to the lender and to secure the Company’s obligations under the note. The secured amended and restated note accrued interest at a per annum fixed rate of 3.25% and was due and payable quarterly in arrears on the last business day of each three-month quarter beginning May 1, 2010. On the effective date of the second amendment, the Company paid the lender $750,000 which was applied to the principal balance of $3,000,000. Beginning May 1, 2010, principal payments were due and payable quarterly in advance. For principal payments due and payable during the period of May 1, 2010 through January 31, 2011, the quarterly principal payment was equal to $45,000; for principal payments due and payable during the period of February 1, 2012 through January 31, 2014, the quarterly principal payment was equal to $90,000; and for principal payments due and payable during the period of February 1, 2014 through the maturity date, the quarterly principal payment was equal to $150,000. In addition to the $750,000 principal paid on the effective date of the amendment, the Company paid principal payments of $135,000 and $180,000 during the years ended December 31, 2010 and 2011, respectively. No principal payments were made during the years ended December 31, 2012 or 2013. As of June 28, 2013 the holder of the Goodman Note agreed to convert the total principal balance owed under the Goodman Note of $1,935,000 and accrued interest of approximately $105,000 into 3,777,324 preferred shares at a conversion price of $0.54 per share. Although the conversion price of the debt was greater than the value of the preferred shares at the time of conversion, the Company did not record a gain on the conversion under the troubled debt restructuring accounting guidance since the transaction occurred between related parties, and thus, was treated as a capital transaction. As of the closing of the Company’s IPO on February 10, 2014, such shares of preferred stock automatically converted into 89,936 shares of common stock. In July 2013, in connection with this conversion, the Company issued to such beneficial owner a warrant to purchase 23,809 shares of common stock at an exercise price of $10.00 per share, which was set at the price of the Company’s common stock sold in the Company’s IPO. The warrants were exercisable for a two year period beginning with the closing of the Company’s IPO on February 10, 2014. In accordance with guidance applicable to accounting for derivative financial instruments that are accounted for as liabilities, the warrants were initially recorded at their fair value and were then re-valued at each reporting date, with changes in the fair value reported in the statements of operations. For the warrants for common shares issued under the Goodman Note agreement, the Company used a probability weighted Black-Scholes valuation model. The fair value of the Goodman Note warrants was included in warrant liabilities until the underlying exercise price was fixed at the closing of the Company’s IPO on February 10, 2014, when the warranty liability balance of approximately $95,000 was reclassified to additional paid-in capital (see Notes 4 and 5). 2008 Convertible Note In December 2008, the Company issued the 2008 Convertible Note in the principal amount of $1,400,000 which was secured by all assets of the Company to an affiliate of a major shareholder. The 2008 Convertible Note accrued interest at a variable rate based on prime per annum payable at maturity, and matured at the earliest occurrence of, (a) the passing of 48 months from inception of the note, (b) the closing date of an acquisition or asset transfer as defined by the note, or (c) the closing date of the issuance and sale of shares of common stock of the Company in the Company’s IPO. Upon the closing of a sale by the Company of its preferred shares in which the Company received an aggregate of at least $20,000,000 in cumulative gross proceeds, including conversion of the convertible loan amount before the maturity date, the unpaid principal and accrued interest would automatically be converted into the number of preferred shares, of the series sold by the Company in such sale, equal to the unpaid principal and accrued interest divided by the per share purchase price of the preferred shares in such sale. The 2008 Convertible Note may have also been converted before the maturity date at the option of the holder at the closing of an equity financing involving the sale of the Company’s preferred shares in which the Company received an aggregate of at least $2,000,000 in cumulative gross proceeds, with a conversion price equal to the per share price included in that equity financing. In July 2013, the Company amended the 2008 Convertible Note to provide that all principal and accrued interest on the note would automatically convert into common stock upon the closing of an IPO at the price per share at which common stock is sold in such IPO. Issued with the 2008 Convertible Note was a warrant to purchase preferred shares issued in the first equity financing to occur subsequent to the execution of the 2008 Convertible Note, and in which the Company would have received at least $2,000,000 in gross aggregate proceeds. The exercise price of the warrant would have been equal to the per share price of preferred shares sold in that equity financing, and the number of shares that may have been exercised was equal to 10% of the principal amount of the convertible loan divided by the exercise price. Early termination of the warrant could occur upon an IPO or if the Company was acquired. The holder of the warrant was to be given 20 days advance notice of such an event, and the warrant would terminate if not exercised before the date of the event. A qualifying equity financing occurred during February 2009, which set the 2008 Convertible Note conversion price and the warrant exercise price at $0.60 per share. In connection with the closing of the Company’s IPO on February 10, 2014, the $1,400,000 principal amount and $233,982 of accrued interest related to the 2008 Convertible Note were converted at $10.00 per share into a total of 163,399 shares of common stock (see Note 4). 2011 Convertible Bridge Notes In February 2011, the Company executed a note and warrant purchase agreement with a major shareholder’s affiliates. In exchange for a series of loans in an aggregate amount equal to $5,000,000 over a period through September 1, 2011, the Company issued the 2011 Convertible Bridge Notes and warrants to purchase preferred shares. The aggregate amount was subsequently raised to $6,000,000 and then $15,000,000 during the year and the funding period was first extended to February 2012 and then to December 2012. Other investors, including related parties, also became party to this arrangement and purchased 2011 Convertible Bridge Notes and warrants. All unpaid principal and interest outstanding was initially payable on December 31, 2011. During 2012, the maturity date was extended to December 31, 2012. The 2011 Convertible Bridge Notes were secured by virtually all of the assets of the Company. The 2011 Convertible Bridge Notes accrued interest at 8%, payable at maturity. The number of preferred shares for which the warrants were exercisable was determined by dividing the warrant coverage amount, which was 20% of the principal amount of the notes issued under the agreement, by the exercise price. Upon the closing of the sale by the Company of its preferred stock in which the Company received an aggregate of at least $20,000,000 in cumulative gross proceeds, including conversion of the 2011 Convertible Bridge Notes, before the maturity date, the unpaid principal and accrued interest would automatically have been converted into the number of preferred shares, of the series sold by the Company in such sale, equal to the unpaid principal and accrued interest divided by the per share purchase price of the preferred shares in such sale. At any time before the maturity date the investor could elect to convert all or any amount of the unpaid principal and accrued interest into the Company’s Series A preferred shares at $0.54 per share. Early termination of the warrants could occur upon an IPO or if the Company was acquired. The holders of the warrants were to be given 20 days advance notice of such an event, and the warrants would terminate if not exercised before the date of the event. In accordance with guidance applicable to accounting for derivative financial instruments that are accounted for as liabilities, the warrants were initially recorded at their estimated fair value and were then re-valued at each reporting date, with changes in the estimated fair value reported in the statements of operations. As of December 31, 2012, the Company had issued the 2011 Convertible Bridge Notes with an aggregate principal amount of approximately $12,336,000. No further note or warrant issuances were made under this agreement during the year ended December 31, 2013. As of December 31, 2012, the Company was in default for payment on the 2011 Convertible Bridge Notes, and no principal payments were made in 2013 prior to their conversion. As of June 28, 2013 the investors under these notes elected to convert the total principal balance owed under the 2011 Convertible Bridge Notes of approximately $12,336,000 and accrued interest of approximately $1,832,000 into 26,237,611 preferred shares at a conversion price of $0.54 per share. Upon the conversion, the exercise price of the related warrants was set at $0.54 per share, and the $236,799 fair value of the warrants was reclassified into additional paid-in capital as of June 28, 2013. Although the conversion price of the debt was greater than the value of the preferred shares at the time of conversion, the Company did not record a gain on the conversion under the troubled debt restructuring accounting guidance since the transaction occurred between related parties, and thus, was treated as a capital transaction. As of the closing of the Company’s IPO on February 10, 2014, such shares of preferred stock automatically converted into 624,705 shares of common stock. 2012 Revolver Notes On January 13, 2012, the Company executed a note and warrant purchase agreement with several shareholders, including a major shareholder, calling for (in addition to the issuance of certain related warrants) the issuance of a series of 2012 Revolver Notes to be issued between January 13, 2012 and April 5, 2012 totaling up to $1,750,000, with an original maturity date in April 2012. The 2012 Revolver Notes were amended on April 5, 2012 to extend the maturity date to May 31, 2012 or July 31, 2012, depending on certain milestones, and to allow the Company to issue up to $5,000,000 in notes payable under this agreement, as needed. The 2012 Revolver Notes were amended again on November 8, 2012 to increase the amount of notes payable the Company could issue to $8,000,000, and to provide that all notes issued under this agreement would have the same maturity date of either November 30, 2012 or December 31, 2012, depending on certain milestones. The 2012 Revolver Notes accrued interest at 10%, payable at maturity. Beginning on the closing of the sale by the Company of its preferred shares in which the Company received an aggregate of at least $20,000,000 in cumulative gross proceeds, the warrants would have been exercisable for preferred shares of the series sold by the Company in such sale, at an exercise price equal to the purchase price per share of the preferred shares sold by the Company in such sale. The number of preferred shares for which the warrants would have been exercisable was determined by dividing the warrant coverage amount, which was 20% of the principal amount of the notes issued under the agreement on the issuance date of such 2012 Revolver Notes, by the exercise price. At any time prior to the maturity date, the investor could elect to convert all or any amount of the unpaid principal and accrued interest into the Company’s Series A preferred stock at $0.54 per share, or if a qualified financing had occurred, at the purchase price per share of the preferred shares sold by the Company in such qualified financing. Early termination of the warrant could occur upon an IPO, or if the Company was acquired. The holders of the warrants were to be given 20 days advance notice of such an event, and the warrants would terminate if not exercised before the date of the event. In accordance with guidance applicable to accounting for derivative financial instruments that are accounted for as liabilities, the warrants were initially recorded at their estimated fair value and were then re-valued at each reporting date, with changes in the estimated fair value reported in the statements of operations. As of December 31, 2012, the Company had issued $5,960,000 in 2012 Revolver Notes. The Company was in default for payment of these notes as of December 31, 2012, and no principal payments were made in 2013 prior to conversion. As of June 28, 2013 the investors under the 2012 Revolver Notes elected to convert the total principal balance of approximately $5,960,000 owed under the 2012 Revolver Notes and accrued interest of approximately $645,000 into 12,230,899 preferred shares at a conversion price of $0.54 per share, pursuant to note conversion agreements of that date. Although the conversion price of the debt was greater than the value of the preferred shares at the time of conversion, the Company did not record a gain on the conversion under the troubled debt restructuring accounting guidance since the transaction occurred between related parties, and thus, was treated as a capital transaction. On September 13, 2013, the exercise price of the warrants was fixed at $0.54 per share, and the fair value of the warrant liability of approximately $144,000 on that date was reclassified to additional paid-in capital. As of the closing of the Company’s IPO on February 10, 2014, such shares of preferred stock automatically converted into 291,212 shares of common stock. Other On September 10, 2012, the Company issued a warrant to its landlord in exchange for a rent deferral through November 30, 2012. The number of Series A preferred shares exercisable under the warrant agreement is determined by dividing the warrant coverage amount of $40,000 by the exercise price. The exercise price of the warrants is $0.60, or, upon the closing of the sale by the Company of its preferred stock in which the Company receives an aggregate of at least $15,000,000 in cumulative gross proceeds, the warrant’s exercise price will be the price per share for which the Company sells its preferred shares in such sale. The term of the warrant is seven years. Early termination of the warrant can occur if the Company is acquired. The holder of the warrant is to be given 20 days advance notice of such an event, and the warrant will terminate if not exercised before the date of the event. The fair value of such liability-classified preferred warrant to purchase an equivalent 1,587 shares of common stock at December 31, 2014 and 2015 is not material to the financial statements. Common Shares 2013 Convertible Bridge Notes The Company executed a convertible note and warrant purchase agreement as of June 28, 2013 with several shareholders, including a major shareholder, relating to the Company’s borrowing as needed of, and issuance of the 2013 Convertible Bridge Notes for, up to $7,000,000. The Company had borrowed $5,165,000 as of the closing of the Company’s IPO on February 10, 2014, against the 2013 Convertible Bridge Notes, including $2,505,000 at each date from a major shareholder. As of December 31, 2013, the maturity date of the 2013 Convertible Bridge Notes was May 31, 2014 with the option to extend by the respective note holders for two successive six month periods. The 2013 Convertible Bridge Notes accrued interest at 8.0% per annum, payable at maturity. The 2013 Convertible Bridge Notes would automatically convert into the Company’s common stock upon the closing of an IPO of at least $8,000,000 in cumulative gross proceeds, at a price equal to the price per share of the Company’s common stock sold in the IPO. The number of common shares for which the warrants were exercisable was determined by dividing the warrant coverage amount, which was 50% of the principal amount of the notes issued under the agreement, by the exercise price of $10.00, which was the price per share of the Company’s common stock sold in the IPO. The warrants are exercisable for a five-year period beginning with the closing of the Company’s IPO on February 10, 2014. Early termination of the warrants can occur upon any capital reorganization, any reclassification of the capital stock, or an asset transfer or acquisition of the Company. The holders of the warrants are to be given 20 days advance notice of such an event, and the warrants will terminate if not exercised prior to the date of the event. In accordance with guidance applicable to accounting for derivative financial instruments that are accounted for as liabilities, the warrants were initially recorded at their fair value and were then re-valued at each reporting date, with changes in the fair value reported in the statements of operations. For the warrants for common shares issued together with the 2013 Convertible Bridge Notes, the Company used a probability weighted Black-Scholes valuation model. The Company recorded approximately $1,612,000 related to the fair value of the warrants issued, as a discount to the carrying value of the debt, accreted to interest expense using the effective interest method from the date of issuance over the life of the debt. These warrants to purchase common stock were valued as of their date of issuance, using the following assumptions: exercise price of between $1.48 and $14.28 per share, contractual term of 5 years, a risk-free interest rate between 1.38% and 1.73%, a dividend yield of 0%, and volatility between 100.0%—105.0%. The value of the warrants using the probability weighted Black-Scholes valuation model accounted for a probability between 75% and 80%, while a fair value of $0 was weighted between 20% and 25%. The fair value of the warrants was included in warrant liabilities until the underlying exercise price was fixed at the closing of the Company’s IPO on February 10, 2014, when the warranty liability balance of approximately $1,563,000 was reclassified to additional paid-in capital (see Notes 2 and 5). Approximately $928,000 related to accretion and write-off of the discount was recognized as interest expense from January 1, 2014 until the closing of the Company’s IPO on February 10, 2014, when the $5,165,000 principal amount and $313,017 of accrued interest related to the 2013 Convertible Bridge Notes were converted at $10.00 per share into a total of 547,803 shares of common stock (see Note 4). Line of Credit Five of the Company’s related parties guaranteed the Company’s Line of Credit (see Note 8) and pledged financial assets to the bank to secure their guaranties, as approved by the Company’s Board of Directors. In return, the Company issued common stock warrants to the guarantors. The fair market value of the collateral provided by the respective guarantors until the closing of the Company’s IPO on February 10, 2014 was $2,578,076. The number of shares subject to the common stock warrants was determined by dividing the warrant coverage amount, which was 50% of the fair market value of the collateral provided by the respective guarantors to secure their respective guaranty obligations to the bank, by the exercise price of $10.00, which was set at the price per share of the Company’s common stock sold in its IPO. The warrants were exercisable for a two year period beginning with the closing of the Company’s IPO on February 10, 2014. In accordance with guidance applicable to accounting for derivative financial instruments that are accounted for as liabilities, the warrants were initially recorded at their fair value and were then re-valued at each reporting date, with changes in the fair value reported in the statements of operations. For the warrants for common shares issued in connection with the Company’s Line of Credit, the Company used a probability weighted Black-Scholes valuation model. The Company recorded approximately $536,000 related to the fair value of the warrants issued, as a discount to the carrying value of the debt, accreted to interest expense on a straight line basis from the date of issuance over the life of the debt. These warrants to purchase common stock were valued as of their date of issuance, using the following assumptions: exercise price between $1.48 and $14.28 per share, contractual term of two years, a risk-free interest rate between 0.38% and 1.38%, a dividend yield of 0%, and volatility between 90.0% and 105.0%. The value of the warrants using the probability weighted Black-Scholes valuation model accounted for a probability of 75%, while a fair value of $0 was weighted 25%. The fair value of the warrants was included in warrant liabilities until the underlying exercise price was fixed at the closing of the Company’s IPO on February 10, 2014, when the warranty liability balance of approximately $514,000 was reclassified to additional paid-in capital (see Notes 2 and 5). Approximately $397,000 related to accretion and write-off of the discount was recognized as interest expense from January 1, 2014 until the closing of the Company’s IPO on February 10, 2014, after which the total outstanding $2,346,000 principal amount and $27,043 of accrued interest were repaid using the net proceeds from the IPO. Other On September 10, 2013, the Company, as part of a lease amendment for its non-cancellable operating lease for its office, laboratory, and warehouse space at its San Diego, California facility, issued a warrant to its landlord with a coverage amount of $502,605. The warrant is exercisable for a five-year period beginning with the closing of the Company’s IPO on February 10, 2014, when such warrant became exercisable for 50,260 shares of common stock and the exercise price was fixed at $10.00 per share. The fair value of the warrant was included in warrant liabilities until the underlying exercise price was fixed at $10.00 per share at the closing of the Company’s IPO on February 10, 2014, when the warranty liability balance of approximately $304,000 was reclassified to additional paid-in capital (see Notes 4 and 5).

Supplier Financing	12 Months Ended
Supplier Financing	Dec. 31, 2015
Debt Disclosure [Abstract]
Supplier Financing	10. Supplier Financing In 2011, the Company purchased certain laboratory equipment under financing agreements with a supplier, a business owned by a member of the Company’s Board of Directors, totaling approximately $256,000. Financing was granted for the purchase of the equipment at a stated interest rate of 0.0%. The Company utilized its average interest rate of 8.0% to amortize the payments and record interest expense, utilizing the effective interest expense method. The remaining balance owed under these financing agreements was approximately $66,000 as of December 31, 2013 and was due in 2013, and was subsequently paid in full using the net proceeds from the Company’s IPO. In 2011, the Company purchased laboratory software under a financing agreement with a supplier for approximately $177,000. This software financing agreement maintained an interest rate of 7.4% per annum. The balance owed under these financing agreements was approximately $62,000 at December 31, 2013 and was subsequently paid in full using the net proceeds from the Company’s IPO. In 2014 and 2015, the Company obtained third-party financing for certain business insurance premiums. The 2014 and 2015 financings bear interest rates of 5.95% and 5.25% per annum, respectively, and all financing is due within one year. The balances due under these annual financing arrangements were approximately $34,000 and $49,000 as of December 31, 2014 and 2015, respectively.

Shareholders' Equity/(Deficit)	12 Months Ended
Shareholders' Equity/(Deficit)	Dec. 31, 2015
Equity [Abstract]
Shareholders' Equity/(Deficit)	11. Shareholders’ Equity/(Deficit) (a) Common Stock The authorized number of shares of common stock at December 31, 2013 was 53,000,000 with a par value of $0.0001 per share. On February 4, 2014, as contemplated by the registration statement covering the Company’s IPO, the Company’s certificate of incorporation was amended to provide for an authorized capitalization of 40,000,000 shares of common stock. (b) Preferred Stock On February 4, 2014, as contemplated by the registration statement covering the Company’s IPO, the Company’s certificate of incorporation was amended to provide for an authorized capitalization of 5,000,000 shares of preferred stock with a par value of $0.0001 per share, reduced from the previously authorized capitalization of 100,000,000 shares of preferred stock. Holders of the Company’s preferred shares were entitled to receive, when and as declared by the Board of Directors and in preference to common shareholders, non-cumulative cash dividends at the rate of 8% per annum of the applicable original issue price on each outstanding preferred share. The original issue price of each share of Series A preferred stock was $0.60. No dividends were declared during 2014. Dividends could not be granted for common shareholders while shares of preferred stock remained outstanding. The holders of preferred shares had the right to one vote for each common share into which the preferred shares were convertible. Upon the liquidation, dissolution, or winding up of the Company, either voluntary or involuntary, the preferred shareholders would have been paid out an amount equal to the original issue price plus all declared and unpaid dividends. If, upon any liquidation, distribution, or winding up of the Company, and the assets of the Company were insufficient to make payment in full to all holders of preferred shares of the liquidation preference, then such assets would have been distributed among the holders of preferred shares ratably in proportion to the full amounts to which they would be entitled. The convertible preferred shares could have been converted into common shares at any time at the option of the holder utilizing the then effective Series A preferred conversion price. All preferred shares would have been automatically converted into common shares utilizing the then effective Series A preferred conversion price upon a) the election of the holders of a majority of the outstanding shares of Series A preferred stock, or b) the closing of a firmly underwritten public offering pursuant to an effective registration statement under the Securities Act of 1933 covering the sale of the Company’s common stock if gross proceeds are at least $20,000,000 and the per share price is at least $25.20. The effective conversion price was equal to the original issue price divided by $25.20 and could have been adjusted for dilutive issuances of common shares, common share rights or options, common share splits and combinations, dividends, and distributions. The effective conversion rate would not have been adjusted for issuances of common share options, warrants or rights to employees, directors, or non-employee service providers.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(d),(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

+ Details

Accounting for Stock-Based Compensation Expense

12 Months Ended

Dec. 31, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Accounting for Stock-Based Compensation Expense

12. Accounting for Stock-Based Compensation Expense

Equity Incentive Plans

In July 2013, the Company adopted a stock-based compensation plan entitled the 2013 Equity Incentive Plan, or the 2013 Equity Incentive Plan. The 2013 Equity Incentive Plan authorized the grant of the following types of awards: (i) nonstatutory stock options, (ii) ISOs, (iii) RSUs, (iv) stock appreciation rights, and (v) performance compensation awards. Awards could have been granted to employees, officers, non-employee board members, consultants, and other service providers of the Company. However, ISOs could not have been granted to non-employees. On January 1, 2015, the number of shares of common stock covered by the 2013 Equity Incentive Plan automatically increased by 222,480 shares, or 5% of the number of common shares then outstanding, to a total of 1,426,051 shares. At the Company’s annual meeting of stockholders held on June 16, 2015, the stockholders approved the Company’s Amended and Restated 2013 Equity Incentive Plan, or the 2013 Plan, which included (i) an increase in the number of shares of common stock authorized for issuance under the 2013 Plan by 1,500,000 shares, and (ii) a provision that shares available for grant under the Company’s 2007 Equity Incentive Plan, or the 2007 Plan, become available for issuance under the 2013 Plan and are no longer available for issuance under the 2007 Plan. As of December 31, 2015, under all plans, a total of 3,068,865 shares were authorized for issuance, 2,218,406 stock options and RSUs had been issued and were outstanding, and 739,373 shares were available for grant.

Stock Options

Non-performance options granted under either plan vest over a maximum period of four years and expire ten years from the date of grant. Non-performance options generally vest either (i) over four years, 25% on the one year anniversary of the date of grant and monthly thereafter for the remaining three years; or (ii) over four years, monthly vesting beginning month-one after the grant and monthly thereafter. Certain non-performance options have been granted which vested 50% on the grant date and monthly thereafter for the remaining two years, and a non-performance option award underlying 50,000 shares of common stock to our interim Chief Financial Officer, or CFO, vests fully upon the earlier of the Company’s employment of a full time CFO or six months from the CFO’s employment commencement date.

The fair value of stock options is determined on the date of grant using the Black-Scholes valuation model. For non-performance awards, such value is recognized as expense over the requisite service period, net of estimated forfeitures, using the straight-line method. The amount and timing of compensation expense recognized for performance awards is based on management’s estimate of the most likely outcome and when the achievement of the performance objectives is probable. The determination of the fair value of stock options is affected by the Company’s stock price, as well as assumptions regarding a number of complex and subjective variables. The volatility assumption is based on a combination of the historical volatility of the Company’s common stock and the volatilities of similar companies over a period of time equal to the expected term of the stock options. The volatilities of similar companies are used in conjunction with the Company’s historical volatility because of the lack of sufficient relevant history for the Company’s common stock equal to the expected term. The expected term of employee stock options represents the weighted-average period the stock options are expected to remain outstanding. The expected term assumption is estimated based primarily on the options’ vesting terms and remaining contractual life and employees’ expected exercise and post-vesting employment termination behavior. The risk-free interest rate assumption is based upon observed interest rates on the grant date appropriate for the term of the employee stock options. The dividend yield assumption is based on the expectation of no future dividend payouts by the Company.

The assumptions used in the Black-Scholes pricing model for options granted during the years ended December 31, 2014 and 2015 are as follows:

	2014		2015
Stock and exercise prices	$2.79 - $9.11		$1.38 - $3.38
Expected dividend yield		0.00%		0.00%
Discount rate-bond equivalent yield	1.56% – 2.06%		1.52% – 1.94%
Expected life (in years)	5.00 – 6.08		5.23 – 6.08
Expected volatility	90.0% – 100.0%		70.0% – 100.0%
Expected forfeiture rate	0.00% – 5.00%		0.00% – 4.00%

Using the assumptions described above, the weighted-average estimated fair value of options granted in 2014 and 2015 were approximately $5.25 and $2.00, respectively.

A summary of stock option activity for 2014 and 2015 is as follows:

						Average
				Weighted		Remaining
	Number of			Average Exercise		Contractual
	Shares			Price Per Share		Term in Years
Outstanding at December 31, 2013		333,106		$	5.14		9.3
Granted		647,298		$	6.71
Exercised		—			—
Cancelled/forfeited/expired		(74,210	)	$	4.77
Outstanding at December 31, 2014		906,194		$	6.29		9.0
Granted		1,323,926		$	2.00
Exercised		—			—
Cancelled/forfeited/expired		(88,979	)	$	4.61
Outstanding at December 31, 2015		2,141,141		$	3.71		9.1
Vested and unvested expected to vest, December 31, 2015		1,940,701		$	5.16		9.0

The intrinsic value of options outstanding at December 31, 2014 and 2015 was zero.

Further information about the options outstanding and exercisable is as follows:

Options Outstanding and Exercisable at December 31, 2014

				Weighted
Weighted				Average
Average		Total Shares		Contractual		Total Shares
Exercise Price		Outstanding		Life (in years)		Exercisable
$	2.79		52,500		9.8		—
$	4.42		103,934		8.8		29,715
$	5.22		413,962		8.8		241,918
$	7.50		43,000		9.2		—
$	8.88		238,500		9.1		—
$	9.11		54,298		9.1		54,298
			906,194

Statements of Shareholders' Equity/(Deficit) (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2014 USD ($)
Debt, principal amount converted	$ 6.6
Accrued interest [Member]
Accrued interest on convertible debt converted	$ 0.5