Property and Equipment, net - Schedule of Property and Equipment, net (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 6,978,055	$ 6,939,666
Less accumulated depreciation and amortization	(5,699,166)	(5,162,364)
Property and equipment, net	1,278,889	1,777,302
Computer and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	476,402	476,402
Lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,567,104	4,437,794
Service equipment placed at customer sites
Property, Plant and Equipment [Line Items]
Property and equipment, gross	58,902	149,823
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,875,647	$ 1,875,647