Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2019	Aug. 10, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	BIOC
Entity Registrant Name	BIOCEPT INC
Entity Central Index Key	0001044378
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity File Number	001-36284
Entity Tax Identification Number	800943522
Entity Address, Address Line One	5810 Nancy Ridge Drive
Entity Address, City or Town	San Diego
Entity Address, State or Province	California
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	320-8200
Entity Common Stock, Shares Outstanding		23,018,235

Condensed Balance Sheets - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash	$ 12,590,597	$ 3,423,373
Accounts receivable, net	2,208,955	1,574,325
Inventories, net	605,472	587,222
Prepaid expenses and other current assets	586,267	425,961
Total current assets	15,991,291	6,010,881
Fixed assets, net	1,219,103	2,739,422
Lease right-of-use assets	2,694,446
Total assets	19,904,840	8,750,303
Current liabilities:
Accounts payable	2,020,580	2,039,718
Accrued liabilities	1,490,808	1,928,393
Supplier financings	264,069
Current portion of equipment financings		641,536
Current portion of lease liabilities	2,046,413
Total current liabilities	5,821,870	4,609,647
Non-current portion of equipment financings		985,015
Non-current portion of lease liabilities	983,419
Non-current portion of deferred rent		113,122
Total liabilities	6,805,289	5,707,784
Commitments and contingencies (see Note 11)
Shareholders’ equity:
Preferred stock, $0.0001 par value, 5,000,000 authorized; 4,417 shares issued and outstanding at December 31, 2018; and 2,133 shares issued and outstanding at June 30, 2019.
Common stock, $0.0001 par value, 150,000,000 authorized; 4,629,174 issued and outstanding at December 31, 2018; 23,018,235 issued and outstanding at June 30, 2019.	2,302	463
Additional paid-in capital	247,387,369	223,499,634
Accumulated deficit	(234,290,120)	(220,457,578)
Total shareholders’ equity	13,099,551	3,042,519
Total liabilities and shareholders’ equity	$ 19,904,840	$ 8,750,303

Condensed Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	2,133	4,417
Preferred stock, shares outstanding	2,133	4,417
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	23,018,235	4,629,174
Common stock, shares outstanding	23,018,235	4,629,174

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net revenues	$ 1,191,323	$ 822,238	$ 2,215,562	$ 1,629,181
Costs and expenses:
Cost of revenues	2,673,323	2,699,671	5,272,687	5,134,557
Research and development expenses	1,148,280	1,019,285	2,371,571	2,089,866
General and administrative expenses	1,676,310	1,708,970	3,358,147	3,647,634
Sales and marketing expenses	1,614,732	1,433,174	2,989,292	3,069,716
Total costs and expenses	7,112,645	6,861,100	13,991,697	13,941,773
Loss from operations	(5,921,322)	(6,038,862)	(11,776,135)	(12,312,592)
Other income/ (expense):
Interest expense	(63,574)	(84,239)	(125,548)	(166,913)
Warrant inducement and other expenses	(1,831,116)	(30,000)	(1,831,116)	(30,000)
Total other income/ (expense):	(1,894,690)	(114,239)	(1,956,664)	(196,913)
Loss before income taxes	(7,816,012)	(6,153,101)	(13,732,799)	(12,509,505)
Income tax expense				(739)
Net loss and comprehensive loss	(7,816,012)	(6,153,101)	(13,732,799)	(12,510,244)
Deemed dividend related to warrants down round provision			(99,743)
Net loss attributable to common shareholders	$ (7,816,012)	$ (6,153,101)	$ (13,832,542)	$ (12,510,244)
Weighted-average shares outstanding used in computing net loss per share attributable to common shareholders:
Basic	20,466,224	2,280,115	16,670,184	2,096,717
Diluted	20,466,224	2,280,115	16,670,184	2,096,717
Net loss per common share:
Basic	$ (0.38)	$ (2.70)	$ (0.83)	$ (5.97)
Diluted	$ (0.38)	$ (2.70)	$ (0.83)	$ (5.97)

Condensed Statements of Shareholders' Equity - USD ($)	Total	January 2019 Financing Transaction [Member]	February 2019 Financing Transaction [Member]	January 2019 Financing Transaction Overallotment [Member]	March 2019 Financing Transaction [Member]	Common Stock [Member]	Common Stock [Member] January 2019 Financing Transaction [Member]	Common Stock [Member] February 2019 Financing Transaction [Member]	Common Stock [Member] January 2019 Financing Transaction Overallotment [Member]	Common Stock [Member] March 2019 Financing Transaction [Member]	SeriesA Convertible Preferred Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] January 2019 Financing Transaction [Member]	Additional Paid-in Capital [Member] February 2019 Financing Transaction [Member]	Additional Paid-in Capital [Member] January 2019 Financing Transaction Overallotment [Member]	Additional Paid-in Capital [Member] March 2019 Financing Transaction [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2017	$ 1,296,034					$ 118						$ 196,545,523					$ (195,249,607)
Beginning balance, shares at Dec. 31, 2017						1,181,179
Stock-based compensation expense	225,263											225,263
Shares and warrants issued, net of issuance costs		$ 13,342,821					$ 110						$ 13,342,711
Shares and warrants issued, net of issuance costs, shares							1,095,153
Adjustment for presentation after reverse stock split						$ 6,576						(6,576)
Net loss	(6,357,143)																(6,357,143)
Ending balance at Mar. 31, 2018	8,506,975					$ 6,804						210,106,921					(201,606,750)
Ending balance, shares at Mar. 31, 2018						2,276,332
Beginning balance at Dec. 31, 2017	1,296,034					$ 118						196,545,523					(195,249,607)
Beginning balance, shares at Dec. 31, 2017						1,181,179
Net loss	(12,510,244)
Ending balance at Jun. 30, 2018	2,527,568					$ 6,823						210,280,596					(207,759,851)
Ending balance, shares at Jun. 30, 2018						2,282,166
Beginning balance at Dec. 31, 2017	1,296,034					$ 118						196,545,523					(195,249,607)
Beginning balance, shares at Dec. 31, 2017						1,181,179
Net loss	(24,600,000)
Ending balance at Dec. 31, 2018	3,042,519					$ 463						223,499,634					(220,457,578)
Ending balance, shares at Dec. 31, 2018						4,629,174					4,417
Beginning balance at Mar. 31, 2018	8,506,975					$ 6,804						210,106,921					(201,606,750)
Beginning balance, shares at Mar. 31, 2018						2,276,332
Stock-based compensation expense	173,694											173,694
Shares issued for restricted stock units						$ 19						(19)
Shares issued for restricted stock units, shares						5,834
Net loss	(6,153,101)																(6,153,101)
Ending balance at Jun. 30, 2018	2,527,568					$ 6,823						210,280,596					(207,759,851)
Ending balance, shares at Jun. 30, 2018						2,282,166
Beginning balance at Dec. 31, 2018	3,042,519					$ 463						223,499,634					(220,457,578)
Beginning balance, shares at Dec. 31, 2018						4,629,174					4,417
Stock-based compensation expense	102,459											102,459
Shares issued upon exercise of common stock warrants	4,748					$ 1						4,747
Shares issued upon exercise of common stock warrants, shares						5,985
Deemed dividends related warrants down round provision												99,743					(99,743)
Shares and warrants issued, net of issuance costs		$ 2,032,311	$ 6,602,735	$ 592,306	$ 7,553,793		$ 99	$ 625	$ 54	$ 595			$ 2,032,212	$ 6,602,110	$ 592,252	$ 7,553,198
Shares and warrants issued, net of issuance costs, shares							990,000	6,250,000	538,867	5,950,000
Shares issued upon conversion of preferred stock						$ 50						(50)
Shares issued upon conversion of preferred stock, shares						503,438					(2,278)
Net loss	(5,916,787)																(5,916,787)
Ending balance at Mar. 31, 2019	14,014,084					$ 1,887						240,486,305					(226,474,108)
Ending balance, shares at Mar. 31, 2019						18,867,464					2,139
Beginning balance at Dec. 31, 2018	3,042,519					$ 463						223,499,634					(220,457,578)
Beginning balance, shares at Dec. 31, 2018						4,629,174					4,417
Deemed dividends related warrants down round provision	99,743
Net loss	(13,732,799)
Ending balance at Jun. 30, 2019	13,099,551					$ 2,302						247,387,369					(234,290,120)
Ending balance, shares at Jun. 30, 2019						23,018,235					2,133
Beginning balance at Mar. 31, 2019	14,014,084					$ 1,887						240,486,305					(226,474,108)
Beginning balance, shares at Mar. 31, 2019						18,867,464					2,139
Stock-based compensation expense	224,641											224,641
Shares issued upon exercise of common stock warrants	4,845,722					$ 415						4,845,307
Shares issued upon exercise of common stock warrants, shares						4,149,445
Shares issued upon conversion of preferred stock, shares						1,326					(6)
Warrant inducement expense	1,831,116											1,831,116
Net loss	(7,816,012)																(7,816,012)
Ending balance at Jun. 30, 2019	$ 13,099,551					$ 2,302						$ 247,387,369					$ (234,290,120)
Ending balance, shares at Jun. 30, 2019						23,018,235					2,133

Condensed Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash Flows from Operating Activities
Net loss	$ (13,732,799)	$ (12,510,244)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	450,984	357,173
Amortization of right-of-use assets	(75,613)
Inventory reserve	8,872	(68,782)
Stock-based compensation	327,100	398,957
Warrant inducement expense	1,831,116
Non-cash interest expense related to credit facility and other financing activities		31,454
Increase/(decrease) in cash resulting from changes in:
Accounts receivable, net	(634,630)	(244,239)
Inventory	(27,122)	30,447
Prepaid expenses and other current assets	233,153	59,545
Accounts payable	(71,720)	435,667
Accrued liabilities	(279,244)	71,749
Accrued interest		10,825
Deferred rent		(54,886)
Net cash used in operating activities	(11,969,903)	(11,482,334)
Cash Flows from Investing Activities:
Purchases of fixed assets	(86,476)	(72,356)
Net cash used in investing activities	(86,476)	(72,356)
Cash Flows from Financing Activities:
Net proceeds from issuance of common stock and warrants	16,779,772	13,342,821
Proceeds from exercise of common stock warrants	2,513,172	0
Proceeds from warrant exercise inducement, net	2,337,298
Payments on finance leases	(277,250)	(111,006)
Payments on supplier and other third-party financings	(129,389)	(229,408)
Payments on credit facility		(1,025,217)
Net cash provided by financing activities	21,223,603	11,977,190
Net increase in Cash	9,167,224	422,500
Cash at Beginning of Period	3,423,373	2,146,611
Cash at End of Period	12,590,597	2,569,111
Cash paid during the period for:
Interest	$ 125,548	134,604
Income taxes		$ 739

Condensed Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($)		1 Months Ended	6 Months Ended		12 Months Ended
	Jan. 30, 2018	May 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Cancelled insurance premiums previously financed through third-parties, remaining principal outstanding balance				$ 31,000
Financed insurance premium through third party financing			$ 393,000	488,000
Financed insurance premium through third party financing, new policies				80,000
Fixed assets purchased under finance lease obligations			149,000	104,000
Purchases of fixed assets			53,000	35,000	$ 25,000	$ 31,000
Exercise price of unregistered warrants	$ 1.20
Class of warrant or rights, term	5 years
Issuance of unregistered warrants to purchase shares of common stock, grant date fair value	$ 9,700,000
Offering fees and costs recorded within common stock issuance costs as an offset to additional paid in capital	1,400,000
Deemed dividends related warrants downround provision	$ 99,000		99,743
Operating lease, right-of-use asset			1,337,240
Operating lease liability			1,533,091
Lease right-of-use assets			1,357,206
Number of common stock warrant exercised		4,100,000
Proceeds from exercise of common stock warrants		$ 4,800,000	$ 2,513,172	$ 0
Warrant Inducement Transaction [Member]
Number of common stock warrant exercised		2,100,000
Proceeds from exercise of common stock warrants		$ 2,300,000
Warrant [Member]
Proceeds from exercise of common stock warrants		$ 2,500,000
Maximum [Member]
Exercise price of unregistered warrants		$ 1.20
Minimum [Member]
Exercise price of unregistered warrants		$ 1.25
Follow-on Public Offering [Member]
Public offering, number of common stock and warrants issued	1,095,153
Stock price	$ 13.50
Exercise price of unregistered warrants	$ 1.20
Class of warrant or rights, term	5 years
Issuance of unregistered warrants to purchase shares of common stock, grant date fair value	$ 9,700,000
Proceeds from issuance of common stock, net of issuance costs	13,300,000
Proceeds from exercise of common stock warrants	$ 0
Follow-on Public Offering [Member] \| Maximum [Member]
Issuance of warrants to purchase shares of common stock	1,095,153

The Company, Business Activities and Basis of Presentation

6 Months Ended

Jun. 30, 2019

Accounting Policies [Abstract]

The Company, Business Activities and Basis of Presentation

1. The Company, Business Activities and Basis of Presentation

The Company and Business Activities

The Company was founded in California in May 1997 and effected a reincorporation to Delaware in July 2013. The Company is an early stage molecular oncology diagnostics company that develops and commercializes proprietary circulating tumor cell, or CTC, and circulating tumor DNA, or ctDNA, assays utilizing a standard blood sample, or liquid biopsy. The Company’s current and planned assays are intended to provide information to aid healthcare providers to identify specific oncogenic alterations that may qualify a subset of cancer patients for targeted therapy at diagnosis, progression or for monitoring in order to identify specific resistance mechanisms. Sometimes traditional procedures, such as surgical tissue biopsies, result in tumor tissue that is insufficient and/or unable to provide the molecular subtype information necessary for clinical decisions. The Company’s assays, performed on blood, have the potential to provide more contemporaneous information on the characteristics of a patient’s disease when compared with tissue biopsy and radiographic imaging. Additionally, commencing in October 2017, the Company’s pathology partnership program, branded as Empower TC^TM, provides the unique ability for pathologists to participate in the interpretation of liquid biopsy results and is available to pathology practices and hospital systems throughout the United States. Further, sales to laboratory supply distributors of our proprietary blood collection tubes, or BCTs, commenced in June 2018, which allow for the intact transport of liquid biopsy samples for research use only, or RUO, from regions around the world.

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.

Basis of Presentation

The accompanying unaudited condensed financial statements and notes are prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, and on the basis that the Company will continue as a going concern (see Note 2). The accompanying unaudited condensed financial statements and notes 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.

On July 6, 2018, the Company’s stockholders approved, and the Company filed, an amendment to the Company’s Certificate of Amendment of Certificate of Incorporation to effect a one-for-thirty reverse stock split of the Company’s outstanding common stock. As such, all references to share and per share amounts in these unaudited condensed financial statements and accompanying notes have been retroactively restated to reflect the one-for-thirty reverse stock split, except for the authorized number of shares of the Company’s common stock of 150,000,000 shares, which was not affected by the one-for-thirty reverse stock split.

The unaudited condensed financial statements included in this Form 10-Q have been prepared in accordance with the U.S. Securities and Exchange Commission, or SEC, instructions for Quarterly Reports on Form 10-Q. Accordingly, the condensed financial statements are unaudited and do not contain all the information required by GAAP to be included in a full set of financial statements. The balance sheet at December 31, 2018 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by GAAP for a complete set of financial statements. The audited financial statements for the year ended December 31, 2018, filed with the U.S. Securities and Exchange Commission, or SEC, with our Annual Report on Form 10-K on March 29, 2019 include a summary of our significant accounting policies and should be read in conjunction with this Form 10-Q. In the opinion of management, all material adjustments necessary to present fairly the results of operations for such periods have been included in this Form 10-Q. All such adjustments are of a normal recurring nature. The results of operations for interim periods are not necessarily indicative of the results of operations for the entire year.

Certain prior period balances have been reclassified to conform to the current period presentation. Such reclassifications had no effect on net loss.

Revenue Recognition and Accounts Receivable

The Company's commercial revenues are generated from diagnostic services provided to patient’s physicians and billed to third-party insurance payers such as managed care organizations, Medicare and Medicaid and patients for any deductibles, coinsurance or copayments that may be due. Commencing on January 1, 2018, the Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers, or ASC 606, which requires that an entity 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. The Company adopted the provisions of ASC 606 using the modified retrospective application method applied to all contracts, which did not impact amounts previously reported by the Company, nor did it require a cumulative effect adjustment upon adoption, as the Company’s method of recognizing revenue under ASC 606 was analogous to the method utilized immediately prior to adoption. Accordingly, there is no need for the Company to disclose the amount by which each financial statement line item was affected as a result of applying the new standard and an explanation of significant changes.

Contracts

For its commercial revenues, while the Company markets directly to physicians, its customer is the patient. Patients do not enter into direct agreements with the Company, however, a patient’s insurance coverage requirements would dictate whether or not any portion of the cost of the tests would be patient responsibility. Accordingly, the Company establishes contracts with commercial insurers in accordance with customary business practices, as follows:


	•		Approval of a contract is established via the order and accession, which are submitted by the patient’s physician.
	•		The Company is obligated to perform its diagnostic services upon receipt of a sample from a physician, and the patient and/or applicable payer are obligated to reimburse the Company for services rendered based on the patient’s insurance benefits.


	•		Payment terms are a function of a patient’s existing insurance benefits, including the impact of coverage decisions with CMS and applicable reimbursement contracts established between the Company and payers, unless the patient is a self-pay patient, whereby the Company bills the patient directly after the services are provided.
	•		Once the Company delivers a patient’s assay result to the ordering physician, the contract with a patient has commercial substance, as the Company is legally able to collect payment and bill an insurer and/or patient, regardless of payer contract status or patient insurance benefit status.


	•		Consideration associated with commercial revenues is considered variable and constrained until fully adjudicated, with net revenues recorded to the extent that it is probable that a significant reversal will not occur.

The Company’s development services revenues are supported by contractual agreements and generated from assay development services provided to entities, as well as certain other diagnostic services provided to physicians, and revenues are recognized upon delivery of the performance obligations in the contract.

Performance Obligations

A performance obligation is a promise in a contract to transfer a distinct good or service, or a bundle of goods or services, to the customer. For its commercial and development services revenues, the Company’s contracts have a single performance obligation, which is satisfied upon rendering of services, which culminates in the delivery of a patient’s assay result(s) to the ordering physician or entity. The duration of time between accession receipt and delivery of a valid assay result to the ordering physician or entity is typically less than two weeks. Accordingly, the Company elected the practical expedient and therefore, does not disclose the value of unsatisfied performance obligations.

Transaction Price

The transaction price is the amount of consideration that the Company expects to collect in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties, such as sales taxes. The consideration expected from a contract with a customer may include fixed amounts, variable amounts, or both. The Company’s gross commercial revenues billed, and corresponding gross accounts receivable, are subject to estimated deductions for such allowances and reserves to arrive at reported net revenues, which relate to differences between amounts billed and corresponding amounts estimated to be subsequently collected, and is deemed to be variable although the variability is not explicitly stated in any contract. Rather, the implied variability is due to several factors, such as the payment history or lack thereof for third-party payers, reimbursement rate changes for contracted and non-contracted payers, any patient co-payments, deductibles or compliance incentives, the existence of secondary payers and claim denials. The Company estimates the amount of variable consideration using the most likely amount approach to estimating variable consideration for third-party payers, including direct patient bills, whereby the estimated reimbursement for services are established by payment histories on CPT codes for each payer, or similar payer types. When no payment history is available, the value of the account is estimated at Medicare rates, with additional other payer-specific reserves taken as appropriate. Collection periods for billings on commercial revenues range from less than 30 days to several months, depending on the contracted or non-contracted nature of the payer, among other variables. The estimates of amounts that will ultimately be realized from commercial diagnostic services for non-contracted payers require significant judgment by management.

The Company limits the amount of variable consideration included in the transaction price to the unconstrained portion of such consideration. Revenue is recognized up to the amount of variable consideration that is not subject to a significant reversal until additional information is obtained or the uncertainty associated with the additional payments or refunds is subsequently resolved. Differences between original estimates and subsequent revisions, including final settlements, represent changes in the estimate of variable consideration and are included in the period in which such revisions are made. The Company monitors its estimates of transaction price to depict conditions that exist at each reporting date. If the Company subsequently determines that it will collect more consideration than it originally estimated for a contract with a customer, it will account for the change as an increase in the estimate of the transaction price in the period identified as an increase to revenue. Similarly, if the Company subsequently determines that the amount it expects to collect from a customer is less than it originally estimated, it will generally account for the change as a decrease in the estimate of the transaction price as a decrease to revenue, provided that such downward adjustment does not result in a significant reversal of cumulative revenue recognized. Revenue recognized from changes in transaction prices was not significant during the three and six months ended June 30, 2018 and 2019.

Allocate Transaction Price

For the Company’s commercial revenues, the entire transaction price is allocated to the single performance obligation contained in a contract with a customer. For the Company’s development services revenues, the contracted transaction price is allocated to each single performance obligation contained in a contract with a customer as performed.

Point-in-time Recognition

The Company’s single performance obligation is satisfied at a point in time, and that point in time is defined as the date a patient’s successful assay result is delivered to the patient’s ordering physician or entity. The Company considers this date to be the time at which the patient obtains control of the promised diagnostic assay service.

Contract Balances

The timing of revenue recognition, billings and cash collections results in accounts receivable recorded in the Company’s condensed balance sheets. Generally, billing occurs subsequent to delivery of a patient’s test result to the ordering physician or entity, resulting in an account receivable.

Practical Expedients

The Company does not adjust the transaction price for the effects of a significant financing component, as at contract inception, the Company expects the collection cycle to be one year or less.

The Company expenses sales commissions when incurred because the amortization period is one year or less, which are recorded within sales and marketing expenses.

The Company incurs certain other costs that are incurred regardless of whether a contract is obtained. Such costs are primarily related to legal services and patient communications. These costs are expensed as incurred and recorded within general and administrative expenses.

Disaggregation of Revenue and Concentration of Risk

The composition of the Company’s net revenues recognized during the three and six-months ended June 30, 2018 and 2019, disaggregated by source and nature, are as follows:

	For the three months ended June 30,				For the six months ended June 30,
	2018		2019		2018		2019
Net revenues from contracted payers*	$	356,000	$	489,901	$	694,760	$	971,320
Net revenues from non-contracted payers		414,742		628,477		828,851		1,125,847
Development services revenues		51,496		45,081		96,130		87,579
Kits and Blood Collection Tubes (BCT)		—		27,864		9,440		30,816
Total net revenues	$	822,238	$	1,191,323	$	1,629,181	$	2,215,562

*Includes Medicare and Medicare Advantage, as reimbursement amounts are fixed.

	For the three months ended June 30,				For the six months ended June 30,
	2018		2019		2018		2019
Net commercial revenues recognized upon delivery	$	770,742	$	1,118,378	$	1,523,611	$	2,009,364
Development services revenues recognized upon delivery		51,496		45,081		96,130		87,579
Commercial revenues recognized upon cash collection		—		—		—		87,803
Kits and Blood Collection Tubes (BCT)		—		27,864		9,440		30,816
Total net revenues	$	822,238	$	1,191,323	$	1,629,181	$	2,215,562

Concentrations of credit risk with respect to revenues are primarily limited to geographies to which the Company provides a significant volume of its services, and to specific third-party payers of the Company’s services such as Medicare, insurance companies, and other third-party payers. The Company’s client base consists of many geographically dispersed clients diversified across various customer types.

The Company's third-party payers that represent more than 10% of total net revenues in any period presented, as well as their related net revenue amount as a percentage of total net revenues, during the three and six-months ended June 30, 2018 and 2019 were as follows:

	For the three months ended June 30,						For the six months ended June 30,
	2018			2019			2018			2019
Medicare and Medicare Advantage		38	%		43	%		39	%		45	%
Blue Cross Blue Shield		12	%		20	%		17	%		17	%
United Healthcare		15	%		8	%		19	%		10	%

The Company's third-party payers that represent more than 10% of total net accounts receivable, and their related net accounts receivable balance as a percentage of total net accounts receivable, at December 31, 2018 and June 30, 2019 were as follows:

	December 31, 2018			June 30, 2019
Blue Cross Blue Shield		22	%		23	%
Medicare and Medicare Advantage		17	%		18	%
United Healthcare		15	%		15	%

Recent Accounting Pronouncements

In February 2016, the FASB issued authoritative guidance, which changes several aspects of the accounting for leases, including the requirement that all leases with durations greater than twelve months be recognized on the balance sheet. The guidance is effective for annual and interim reporting periods in fiscal years beginning after December 15, 2018. Effective January 1, 2019, the Company adopted the guidance and elected the optional transition method to account for the impact of the adoption with a cumulative-effect adjustment in the period of adoption and did not restate prior periods. The Company also elected the practical expedient package as permitted under the transition guidance. As of January 1, 2019, the Company recorded a right-of-use asset and liability upon adoption of the guidance (See Note 7).

In August 2017, the FASB issued authoritative guidance that expands and refines hedge accounting for both nonfinancial and financial risk components and align the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. This guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early application is permitted. The Company adopted this guidance for the fiscal year beginning on January 1, 2019 and determined that the adoption of this guidance does not have a material impact on its financial statements or disclosures because the Company does not currently hold any financial instruments accounted for as a hedging activity.

In February 2018, the FASB issued authoritative guidance allowing a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from a tax bill, “H.R.1, An Act to Provide for Reconciliation Pursuant to Titles II and V of the Concurrent Resolution on the Budget for Fiscal Year 2018,” or the Tax Cuts and Jobs Act, enacted on December 22, 2017. These amendments eliminate the stranded tax effects resulting from the Tax Cuts and Jobs Act. However, because these amendments only relate to the reclassification of the income tax effects of the Tax Cuts and Jobs Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. This guidance also requires certain disclosures about stranded tax effects. This guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. The Company adopted this guidance for the fiscal year beginning on January 1, 2019 which did not have a material impact on its financial statements or disclosures because the Company does not currently maintain any stranded tax effects in accumulated other comprehensive income.

In June 2018, the FASB issued authoritative guidance simplifying the accounting for nonemployee stock-based compensation and largely aligning such compensation with the accounting requirements for employee stock-based awards. For public companies, this guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. The Company adopted this guidance for the fiscal year beginning on January 1, 2019 and determined that the adoption of this guidance does not have a material impact on its financial statements or disclosures.

In November 2018, the FASB issued authoritative guidance clarifying the interaction between Collaborative Arrangements (Topic 808) and Revenue from Contracts with Customers (Topic 606) to address diversity in practice related to how companies account for collaborative arrangements. For public companies, this guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of Revenue from Contracts with Customers (Topic 606). The Company currently intends to adopt this guidance upon the effective date and does not anticipate that the adoption of this guidance will have a material impact on its financial statements or disclosures.

Liquidity and Going Concern Uncertainty

6 Months Ended

Jun. 30, 2019

Accounting Policies [Abstract]

Liquidity and Going Concern Uncertainty

2. Liquidity and Going Concern Uncertainty

As of June 30, 2019, cash totaled $12.6 million and the Company had an accumulated deficit of $234.3 million. For the year ended December 31, 2018 and the six months ended June 30, 2019, the Company incurred net losses of $24.6 million and $13.7 million, respectively. At June 30, 2019, the Company had aggregate net interest-bearing indebtedness of $1.8 million, of which $899,000 was due within one year, in addition to $3.5 million of other non-interest bearing current liabilities. Additionally, in February 2016, the Company signed a firm, non-cancelable, and unconditional commitment in an aggregate amount of $1,062,500 with a vendor to purchase certain inventory items, payable in minimum quarterly amounts of $62,500 through May 2020, under which $216,000 remained outstanding at June 30, 2019 (see Note 11). These factors raise substantial doubt about the Company’s ability to continue as a going concern for the one-year period following the date that these financial statements were issued. The accompanying financial statements and notes have been prepared assuming that the Company will continue as a going concern. The accompanying financial statements and notes 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 for 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 laboratory services. 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 growth in net revenues to achieve and sustain income from operations.

On January 30, 2018, the Company received net cash proceeds of approximately $13.3 million from the closing of a follow-on public offering of 1,095,153 shares of its common stock and warrants to purchase up to an aggregate of 1,095,153 shares of its common stock at a combined offering price of $13.50 per unit. Subsequent to the closing of this offering, no additional cash proceeds have been received from the exercise of warrants sold in this offering, with approximately $1.3 million in gross warrant proceeds remaining outstanding and available to be exercised at $1.20 per share, which is subject to down round adjustment, until their expiration in January 2023. Pursuant to the down round adjustment feature of the January 2018 warrants, the exercise price of these warrants was adjusted to the $1.20 offering price per share in the February 2019 financing transaction.

In May 2018, the SEC declared effective a shelf registration statement filed by the Company, which expires in May 2021. 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 its public float is less than $75 million.

On August 13, 2018, the Company completed a rights offering pursuant to an effective registration statement. Pursuant to the rights offering, the Company sold an aggregate of 11,587 units consisting of an aggregate of 11,587 shares of Series A Convertible Preferred Stock and 2,549,140 warrants, with each warrant exercisable for one share of its common stock at an exercise price of $4.53 per share, resulting in net proceeds to the Company of approximately $10.1 million, after deducting expenses relating to the Rights Offering, including dealer-manager fees and expenses, and excluding any proceeds received upon exercise of any warrants.

On September 20, 2018, the Company completed an offering of 642,438 shares of the Company’s common stock and pre-funded warrants to purchase up to an aggregate of 120,000 shares of its common stock. The shares were sold at a purchase price of $3.285 per share and the pre-funded warrants were sold at a purchase price of $3.275 per pre-funded warrant which represents the per share purchase price for the shares less the $0.01 per share exercise price for each such pre-funded warrant. The net proceeds to the Company from the offering were approximately $2.2 million, after deducting expenses related to the offering including dealer-manager fees and expenses, and excluding any proceeds received upon exercise of any warrants. In addition, in a concurrent private placement, the Company issued to purchasers a warrant to purchase one share of the Company’s common stock for each share and pre-funded warrant purchased for cash in the offering. All warrants issued in this offering initially had an exercise price of $3.16 per share, are exercisable upon the six-month anniversary of issuance and expire five years from such date.

On January 18, 2019, the Company completed an offering of 990,000 shares of the Company’s common stock. The shares were sold at a purchase price of $2.25 per share and the net proceeds to the Company from this offering were approximately $2.0 million, after deducting expenses related to the offering including dealer-manager fees and expenses.

On February 12, 2019, the Company received net cash proceeds of approximately $6.6 million from the closing of a follow-on public offering of 6,250,000 shares of its common stock and warrants to purchase up to an aggregate of 6,250,000 shares of its common stock at a combined offering price of $1.20 per unit. In addition, the Company sold warrants to purchase up to an aggregate of 937,500 shares of the Company’s common stock in connection with the partial exercise of the over-allotment option granted to the underwriters. Upon closing of the transaction, warrants to purchase 915,000 shares were issued pursuant to the placement agents’ partial exercise of their overallotment. Subsequent to the closing of this offering, no additional cash proceeds have been received from the exercise of warrants sold in this offering. On March 11, 2019, the underwriters exercised their overallotment option for 538,867 shares of the Company’s common stock related to the February 12, 2019 follow-on offering, purchasing shares at $1.20 per share for net cash proceeds of approximately $592,000.

In May 2019, the Company received net proceeds of approximately $2.3 million related to the May 2019 Warrant Exercise Inducement Offering as well as an additional $2.5 million from other warrant exercises. The warrants exercised had exercise prices ranging from $1.20 to $1.25 per share and the total number of shares of common stock issued upon exercises both in connection with the Warrant Exercise Inducement Offering and other warrant exercises was approximately 4.2 million shares.

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, cash received from the exercise of outstanding common stock warrants, 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.

Sales of Equity Securities

6 Months Ended

Jun. 30, 2019

Equity [Abstract]

Sales of Equity Securities

3. Sales of Equity Securities

On January 30, 2018, the Company received net cash proceeds of approximately $13.3 million from the closing of a follow-on public offering of 1,095,153 shares of its common stock and warrants to purchase up to an aggregate of 1,095,153 shares of its common stock at a combined offering price of $13.50 per unit, with $1.4 million of costs directly associated with the offering recorded as an offset to additional paid-in capital under applicable accounting guidance. All warrants sold in this offering have an exercise price of $1.20 per share, which is subject to down round adjustment, are exercisable immediately and expire five years from the date of issuance. The aggregate estimated grant date fair value of $9.7 million was recorded as an offset to additional paid-in capital upon the closing of this offering (see Note 4).

In May 2018, the SEC declared effective a shelf registration statement filed by the Company, which expires in May 2021. The shelf registration statement allows the Company to issue any combination of our 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 our public float is less than $75 million.

On August 13, 2018, the Company completed a rights offering. Pursuant to the rights offering, the Company sold an aggregate of 11,587 units consisting of an aggregate of 11,587 shares of Series A Preferred Stock and 2,549,140 warrants, with each warrant exercisable for one share of our common stock at an exercise price of $4.53 per share, resulting in net proceeds to the Company of approximately $10.1 million, after deducting expenses relating to the rights offering, including dealer-manager fees and expenses, and excluding any proceeds received upon exercise of any warrants. Each share of Series A Preferred Stock will be convertible, at the Company’s option at any time on or after the first anniversary of the closing of the Rights Offering or at the option of the holder at any time, into the number of shares of the Company’s common stock, par value $0.0001 per share determined by dividing the $1,000 stated value per share of the Series A Preferred Stock by a conversion price of $4.53 per share. In addition, the conversion price per share is subject to adjustment for stock dividends, distributions, subdivisions, combinations or reclassifications. Holders of Series A Preferred Stock shall be entitled to receive dividends (on an as-if-converted-to-common-stock basis) in the same form as dividends actually paid on shares of the Common Stock when, as and if such dividends are paid on shares of Common Stock. The Series A Preferred Stock have no voting rights. Upon the Company’s liquidation, dissolution or winding-up, whether voluntary or involuntary, holders of Series A Preferred Stock will be entitled to receive out of the assets, whether capital or surplus, of the Company the same amount that a holder of Common Stock would receive if the Series A Preferred Stock were fully converted (disregarding for such purpose any conversion limitations thereunder) to Common Stock, which amounts shall be paid pari passu with all holders of Common Stock. The Company is not obligated to redeem or repurchase any shares of Series A Preferred Stock.

On September 20, 2018, the Company completed an offering of 642,438 shares of the Company’s common stock and prefunded warrants to purchase up to an aggregate of 120,000 shares of its common stock. The shares were sold at a purchase price of $3.285 per share and the pre-funded warrants were sold at a purchase price of $3.275 per pre-funded warrant which represents the per share purchase price for the shares less the $0.01 per share exercise price for each such pre-funded warrant. The net proceeds to the Company from this offering were approximately $2.2 million, after deducting expenses related to the offering including dealer-manager fees and expenses, and excluding any proceeds received upon exercise of any warrants. In addition, in a concurrent private placement, the Company issued to purchasers a warrant to purchase one share of the Company’s common stock for each share and pre-funded warrant purchased for cash in the offering. All warrants issued in this offering have an exercise price of $3.16 per share, are exercisable upon the six-month anniversary of issuance and expire five years from such date.

On February 12, 2019, the Company received net cash proceeds of approximately $6.6 million as a result of the closing of a follow-on public offering of 6,250,000 shares of its common stock and warrants to purchase up to an aggregate of 6,250,000 shares of its common stock at a combined offering price of $1.20 per unit. All warrants sold in this offering have an exercise price of $1.20 per share, are exercisable immediately and expire five years from the date of issuance. In addition, the Company sold warrants to purchase up to an aggregate of 937,500 shares of the Company’s common stock in connection with the partial exercise of the over-allotment option granted to the underwriters. Upon closing of the transaction, warrants to purchase 915,000 shares were issued pursuant to the placement agents’ partial exercise of their overallotment. Subsequent to the closing of this offering, no additional cash proceeds have been received from the exercise of warrants sold in this offering. On March 11, 2019, the underwriters exercised their overallotment option for 538,867 shares of the Company’s common stock related to the February 12, 2019 follow-on offering, purchasing shares at $1.20 per share for net cash proceeds of approximately $592,000.

Pursuant to the down round adjustment feature of the January 2018 warrants, the exercise price of these warrants was adjusted to the $1.20 price per share offering price in the February 2019 financing transaction.

On March 19, 2019, the Company received net cash proceeds of approximately $7.5 million as a result of completing a registered direct offering of 5,950,000 shares at a negotiated purchase price of $1.37 per share. In addition, in a concurrent private placement, the Company issued to purchasers a warrant to purchase one share of the Company’s common stock for each share purchased for cash in the offering. All warrants issued in this offering have an exercise price of $1.25 per share, are exercisable immediately upon issuance and expire 5.5 years following the date of issuance.

In May 2019, the Company received cash proceeds of approximately $2.5 million from the exercise of 2,086,479 February 2019 warrants at $1.20 per share.

On May 28, 2019, the Company entered into Warrant Exercise Agreements, or the Exercise Agreements, with certain of the holders of its existing warrants, or the Exercising Holders. Pursuant to the Exercise Agreements, the Exercising Holders and the Company agreed that, subject to any applicable beneficial ownership limitations, the Exercising Holders would cash exercise up to 20% of their Existing Warrants, or the Investor Warrants, into shares of Common Stock underlying such Existing Warrants, or the Exercised Shares. In order to induce the Exercising Holders to cash exercise the Investor Warrants, the Exercise Agreements provided for the issuance of new warrants, or the New Warrants, with such New Warrants to be issued in an amount equal to 75% of the number of Exercised Shares underlying any Investor Warrants that was cash exercised by July 15, 2019. The New Warrants were exercisable upon issuance and terminate on the date that is five-years and six-months following the initial exercise date. The New Warrants have an exercise price per share of $1.31. A total of 2,062,966 Investor Warrants were exercised contemporaneously with the execution of the Exercise Agreements resulting in total proceeds to the Company of $2.3 million, net of investment banking fees. The warrants issued in connection with the Exercise Agreement were considered inducement warrants and are classified in equity. The fair value of the warrants issued was approximately $1.8 million (see valuation assumptions in Note 4). The fair value of the inducement warrants of $1.8 million was expensed as warrant inducement expense in the accompanying consolidated statements of operations for the three and six months ended June 30, 2019.

On July 15, 2019, the Company entered into amendments (the “Amendments”) to the Exercise Agreements. Pursuant to the Amendments, the period during which the Exercising Holders may elect to exercise for cash the Existing Warrants in exchange for new warrants to purchase Common Stock to be issued in an amount equal to 75% of the number of shares of Common Stock exercised under the Existing Warrants was extended from July 15, 2019 to July 31, 2019. There had been no additional warrants exercised under the Amendments as the date this Quarterly Report on 10-Q was filed.

Fair Value Measurement

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Fair Value Measurement

4. Fair Value Measurement

The estimated nonrecurring fair value measurements associated with fixed asset purchases recorded as right-of-use asset finance lease obligations totaling approximately $149,000 during the six months ended June 30, 2019 were calculated as the present value of the lease payments based on contractual payment amounts and estimated market rates. Upon adoption of guidance in ASC Topic 842 Leases, the estimated fair value of the right-of-use operating lease asset was recorded based on present value of future lease payments based contractual payment amounts and estimated market rates in effect.

Other Fair Value Measurements

As of the closing of the Company’s January 30, 2018 offering, the grant date fair value of the warrants issued to purchase up to 1,095,153 shares of common stock was estimated to be approximately $8.82 per share, or a total of approximately $9.7 million, was recorded as an offset to additional paid-in-capital on a relative fair value basis. The warrants sold in this offering have an exercise price of $1.20 per share, which is subject to down round adjustment, and expire five years from the date of issuance. The fair value of the warrants was estimated using a Monte Carlo simulation valuation model using Geometric Brownian Motion, incorporating anticipated future financing events, with the following assumptions:

Beginning stock price	$	10.17
Exercise price	$	15.00
Expected dividend yield		0.00	%
Discount rate-bond equivalent yield		2.48	%
Expected life (in years)		5.00
Expected volatility		99.0	%

As of the closing of the Company’s February 12, 2019 offering, the estimated grant date fair value of approximately $0.95 per share associated with the warrants to purchase up to 7,165,000 shares of common stock issued in this offering, or a total of approximately $6.8 million, was recorded as an offset to additional paid-in capital on a relative fair value basis. All warrants sold in this offering have an exercise price of $1.20 per share, are exercisable immediately and expire five years from the date of issuance. The fair value of the warrants was estimated using a Black-Scholes model with the following assumptions:

Beginning stock price	$	1.05
Exercise price	$	1.20
Expected dividend yield		0.00	%
Discount rate-bond equivalent yield		2.49	%
Expected life (in years)		5.00
Expected volatility		147.7	%

As of the closing of the Company’s March 19, 2019 offering, the estimated grant date fair value of approximately $1.01 per share associated with the warrants to purchase up to 5,950,000 shares of common stock issued in this offering, or a total of approximately $6.0 million, was recorded as an offset to additional paid-in capital on a relative fair value basis. All warrants sold in this offering have an exercise price of $1.25 per share, are exercisable immediately and expire 5.5 years from the date of issuance. The fair value of the warrants was estimated using a Black-Scholes model with the following assumptions:

Beginning stock price	$	1.12
Exercise price	$	1.25
Expected dividend yield		0.00	%
Discount rate-bond equivalent yield		2.44	%
Expected life (in years)		5.50
Expected volatility		140.0	%

As of the closing of the Company’s May 30, 2019 warrant inducement transaction, the estimated grant date fair value of approximately $1.18 per share associated with the warrants to purchase up to 1,547,226 shares of common stock issued in this offering, or a total of approximately $1.8 million, was recorded as a warrant inducement expense with an offset to additional paid-in capital. All warrants issued in this warrant inducement transaction have an exercise price of $1.31 per share, are exercisable immediately and expire 5.5 years from the date of issuance. The fair value of the warrants was estimated using a Black-Scholes model with the following assumptions:

Beginning stock price	$	1.29
Exercise price	$	1.31
Expected dividend yield		0.00	%
Discount rate-bond equivalent yield		2.05	%
Expected life (in years)		5.50
Expected volatility		145.9	%

- 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

6 Months Ended

Jun. 30, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Balance Sheet Details

5. Balance Sheet Details

The following provides certain balance sheet details:

	December 31,			June 30,
	2018			2019
Fixed Assets
Machinery and equipment	$	2,818,583		$	2,823,938
Furniture and office equipment		157,391			157,391
Computer equipment and software		1,437,408			1,552,891
Leasehold improvements		570,173			570,174
Financed equipment		2,573,955			—
Construction in process		116,640			134,859
Total fixed assets, gross		7,674,150			5,239,253
Less accumulated depreciation and amortization		(4,934,728	)		(4,020,150	)
Total fixed assets, net	$	2,739,422		$	1,219,103
Accrued Liabilities
Accrued payroll	$	255,426		$	194,917
Accrued vacation		535,682			573,655
Accrued bonuses		712,574			447,432
Accrued sales commissions		62,767			87,224
Current portion of deferred rent		158,342			—
Accrued other		203,602			187,580
Total accrued liabilities	$	1,928,393		$	1,490,808

During the six months ended June 30, 2019 there were no disposals and $139,000 of fixed assets were acquired. Upon adoption of the lease guidance in ASC Topic 842, Leases (ASC 842), equipment with a total cost of $2,574,000 and accumulated depreciation of $1,135,000 were reclassified to leases right-of-use assets on the Company’s balance sheet (see Note 7). Depreciation expense for the six months ended June 30, 2018 was $357,173 and for the six months ended June 30, 2019 was $450,984. Depreciation expense for the three months ended June 30, 2018 was $177,401 and for the three months ended June 30, 2019 was $228,856.

April 2014 Credit Facility

6 Months Ended

Jun. 30, 2019

Debt Disclosure [Abstract]

April 2014 Credit Facility

6. April 2014 Credit Facility

On April 30, 2014, the Company received net cash proceeds of approximately $4,898,000 pursuant to the execution of the April 2014 Credit Facility. Upon entering into the April 2014 Credit Facility, the Company was required to pay the lender a facility fee of $50,000 in conjunction with the funding of the term loan. The April 2014 Credit Facility was secured by substantially all of the Company’s personal property other than its intellectual property. The term loan under the April 2014 Credit Facility bore 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 lender in consecutive monthly installments following such interest-only period. The term loan under the April 2014 Credit Facility matured on July 1, 2018. Under the original terms of the underlying agreement, the Company was also required to make a final payment to the lender equal to 5.5% of the original principal amount of the term loan funded. Upon maturity of the April 2014 Credit Facility on July 1, 2018, security interest in the Company’s personal property was released by the lender.

A warrant to purchase up to 588 shares of the Company’s common stock at an exercise price of $424.80 per share with a term of 10 years was issued to Oxford Finance LLC on April 30, 2014. Issuance costs of approximately $102,000 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 approximately $4,898,000. The estimated fair value of the warrant issued of approximately $233,000 was also recorded as a discount to outstanding debt as of the closing date. The discounts and other issuance costs were amortized to interest expense utilizing the effective interest method over the underlying term of the loan.

Leases

6 Months Ended

Jun. 30, 2019

Leases [Abstract]

Leases

7. Leases

Effective January 1, 2019, the Company adopted US GAAP accounting rules in ASC Topic 842, Leases (ASC 842), using the modified retrospective method. The Company elected to follow the package of practical expedients provided under the transition guidance within ASC 842, and accordingly, did not reassess whether any expired or existing contracts are or contain leases, did not reassess expired or existing leases, and did not reassess initial direct costs for any existing leases. Upon adoption, the Company recorded an operating lease right-of-use asset and an operating lease liability on the balance sheet. In addition, assets under equipment leases previously classified as capital leases within Property, Plant and Equipment on the Company’s balance sheet were reclassified to finance lease right-of-use assets upon adoption of the guidance. Right-of-use assets and obligations were recognized based on the present value of remaining lease payments over the lease term. As the Company’s operating lease does not provide an implicit rate, an estimated incremental borrowing rate was used based on the information available at the adoption date in determining the present value of lease payments. Operating lease expense is recognized on a straight-line basis over the lease term. Variable lease costs such as common area costs and other operating costs are expensed as incurred. Leases with an initial term of 12 months or less are not recorded on the balance sheet.

Finance Leases

The Company leases certain laboratory equipment under arrangements previously accounted for as capital leases, classified on the Company’s balance sheet as fixed assets and related lease liabilities and depreciated on a straight line basis over the lease term. Upon adoption of ASC 842, leased equipment previously classified as fixed assets totaling $1.4 million in net book value were reclassified to lease right-of-use assets in accordance with the guidance. The equipment under finance leases is depreciated on a straight-line basis over periods ranging from approximately 3 to 7 years. The total gross value of equipment capitalized under such lease arrangements was approximately $2,574,000 and $2,723,000 at December 31, 2018 and June 30, 2019, respectively. Total accumulated depreciation related to equipment under finance leases was approximately $1,135,000 and $1,366,000 at December 31, 2018 and June 30, 2019, respectively. Total depreciation expense related to equipment under finance leases during the three months ended June 30, 2018 and 2019 was approximately $89,000, and was approximately $156,000 and $231,000 during the six months ended June 30, 2018 and 2019, respectively.

On January 31, 2019, the Company executed an equipment financing commitment with a third-party lender for total proceeds of approximately $149,000, which was funded by the lender on February 1, 2019. Under the terms of the equipment financing agreement, which was accounted for as a finance lease transaction, the principal balance plus interest for the equipment are to be repaid in full after 36 monthly installments of $5,013 totaling approximately $180,000 through February 2022.

Operating Lease

The Company leases its primary laboratory and office facilities in San Diego, California. This lease is classified as an operating lease in accordance with the ASC 842 guidance. The average monthly cash payment for the operating lease is approximately $120,000 per month, and the lease term ends on July 31, 2020. The Company recorded a lease right-of-use asset and lease liability of $1,930,000 and $2,201,000, respectively, as of January 1, 2019, based on present value of payments and an incremental borrowing rate of 4.5%.

In addition, the Company reviews agreements at inception to determine if they include a lease, and when they do, uses its incremental borrowing rate or implicit interest rate to determine the present value of the future lease payments.

The following schedule sets forth the components of right-of-use lease assets as of December 31, 2018 and June 30, 2019 as follows:

	December 31,		June 30,
	2018		2019
Lease right-of-use assets:
Operating	$	—	$	1,337,240
Finance		—		1,357,206
Total	$	—	$	2,694,446

The following schedule sets forth the current portion of operating and finance lease liabilities as of December 31, 2018 and June 30, 2019:

	December 31,		June 30,
	2018		2019
Current portion of lease liabilities:
Operating	$	—	$	1,411,385
Finance		—		635,028
Total	$	—	$	2,046,413

The following schedule sets forth the long-term portion of operating and finance lease liabilities as of December 31, 2018 and June 30, 2019:

	December 31,		June 30,
	2018		2019
Long-term portion of lease liability:
Operating	$	—	$	121,706
Finance		—		861,713
Total	$	—	$	983,419

The following schedule represents the components of lease expense for the three and six months ended June 30, 2019 and 2018:

	For the three months ended June 30,				For the six months ended June 30,
	2018		2019		2018		2019
Lease costs
Finance lease cost
Amortization of right-of-use assets		—	$	119,599		—	$	229,929
Interest on lease liabilities		—		63,574		—		125,548
Operating lease cost		—		318,005		—		636,010
Total	$	—	$	501,178	$	—	$	991,487

The following schedule sets forth the remaining future minimum lease payments outstanding under finance and operating leases, as well as corresponding remaining sales tax and maintenance obligation payments that are expensed as incurred and due within each respective year ending December 31, as well as the present value of the total amount of the remaining minimum lease payments as of June 30, 2019:

	Finance					Operating
	Minimum			Maintenance and		Minimum
	Lease			Sales Tax Obligation		Lease
	Payments			Payments		Payments
2019	$	351,616		$	46,833	$	718,740
2020		611,772			77,298		855,136
2021		365,168			56,136		—
2022		268,056			62,778		—
Thereafter		286,746			45,710		—
Total payments		1,883,358			288,755		1,573,876
Less amount representing interest		(388,607	)		—		(40,785	)
Present value of payments	$	1,494,751		$	288,755	$	1,533,091

The following schedule sets forth supplemental cash flow information related to operating and finance leases as of June 30, 2019:

	For the six months ended
	June 30, 2019
Other information
Operating cash flows from finance leases	$	125,548
Operating cash flows from operating leases	$	711,624
Financing cash flows from finance leases	$	277,250

The aggregate weighted average remaining lease term was 3.19 years on finance leases and 1.09 years on operating leases as of June 30, 2019. The aggregate weighted average discount rate was 21.17% on finance leases and 4.5% on operating leases as of June 30, 2019. During the six months ended June 30, 2019, the Company added $149,000 of right of use assets in exchange for finance lease liabilities. In addition, upon adoption of the accounting guidance in ASC 842, $1.4 million of net machinery and equipment was reclassified to lease right-of-use assets related to assets under finance leases and $1.9 million of right-of-use facility lease was recorded under operating lease.

Stock-Based Compensation	6 Months Ended
Stock-Based Compensation	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]