Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 34,847,086	$ 8,432,600
Short-term investments available-for-sale, at fair value	3,037,393	22,681,049
Accounts receivable	3,933,361	5,012,678
Inventory, net of allowance of $39,403 at both September 30, 2019 and December 31, 2018	1,191,742	1,306,609
Prepaid expenses and other	854,632	519,002
Total current assets	43,864,214	37,951,938
Restricted cash	3,270,247	3,270,247
Operating lease right-of-use assets	1,370,189
Property and equipment, net	2,183,443	2,373,790
Other non-current assets	239,713	175,305
Total assets	50,927,806	43,771,280
Current liabilities:
Accounts payable	3,016,538	1,849,921
Accrued liabilities	1,795,129	3,358,465
Contract liabilities - current	306,154	332,711
NuvoGen obligation - current	1,327,922	1,290,234
MidCap Term Loan payable - current	1,166,667
Operating lease liabilities - current	773,376
Other current liabilities	34,011	186,043
Total current liabilities	8,419,797	7,017,374
NuvoGen obligation - non-current, net of discount	4,650,924	5,702,519
Convertible note - net of debt issuance costs	2,984,304	2,974,213
MidCap Term Loan payable - non-current, net of discount and debt issuance costs	5,654,410	6,704,641
Operating lease liabilities - non-current	820,888
Other non-current liabilities	280,979	280,471
Total liabilities	22,811,302	22,679,218
Commitments and Contingencies (Note 15)
Stockholders’ equity:
Common stock, $0.001 par value; 200,000,000 shares authorized at September 30, 2019 and December 31, 2018, 58,031,230 shares issued and outstanding at September 30, 2019 and 28,585,449 shares issued and outstanding at December 31, 2018	58,031	28,585
Additional paid-in-capital	193,953,125	172,086,909
Accumulated other comprehensive income (loss)	33,675	(3,453)
Accumulated deficit	(165,928,327)	(151,019,979)
Total stockholders’ equity	28,116,504	21,092,062
Total liabilities and stockholders' equity	$ 50,927,806	$ 43,771,280