Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Document Information [Line Items]
Entity Registrant Name	OPGEN INC
Entity Central Index Key	0001293818
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Trading Symbol	OPGN
Entity Common Stock, Shares Outstanding		12,537,454
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2015