Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Nov. 08, 2019
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
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 Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period true  
Entity Common Stock, Shares Outstanding   23,018,235
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 001-36284  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 80-0943522  
Entity Address, Address Line One 5810 Nancy Ridge Drive  
Entity Address, City or Town San Diego  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 92121  
City Area Code 858  
Local Phone Number 320-8200  
Title of 12(b) Security Common Stock, par value $.0001 per share  
Security Exchange Name NASDAQ  
Entity Shell Company false  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes