Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 18,884,468	$ 7,619,748
Short-term investments available-for-sale, at fair value	11,632,160	25,410,222
Restricted cash		3,270,247
Accounts receivable	1,370,201	3,164,176
Inventory, net of allowance of $27,770 at September 30, 2020 and $39,403 at December 31, 2019	1,538,553	1,269,667
Prepaid expenses and other	946,979	633,522
Total current assets	34,372,361	41,367,582
Operating lease right-of-use assets	746,185	1,209,145
Property and equipment, net	1,526,698	2,240,133
Other non-current assets	64,861	302,409
Total assets	36,710,105	45,119,269
Current liabilities:
Accounts payable	875,236	1,662,583
Accrued liabilities	1,386,825	1,870,296
Contract liabilities - current	348,274	426,014
NuvoGen obligation - current	645,949	1,152,233
Current portion of long-term debt, net	2,266,884	2,987,667
Operating lease liabilities - current	436,663	758,932
Other current liabilities	26,620	41,134
Total current liabilities	5,986,451	8,898,859
NuvoGen obligation - non-current, net of discount	4,455,968	4,498,777
Long-term debt, net of current portion and discount and debt issuance costs	9,446,985	6,871,545
Operating lease liabilities - non-current	390,233	636,340
Other non-current liabilities	229,114	244,114
Total liabilities	20,508,751	21,149,635
Commitments and Contingencies (Note 15)
Stockholders’ equity:
Series A convertible preferred stock, $0.001 par value; 23,770 shares authorized at September 30, 2020 and no shares authorized at December 31, 2019; 23,770 shares issued and outstanding at September 30, 2020 and no shares issued and outstanding at December 31, 2019	24
Common stock, $0.001 par value; 200,000,000 shares authorized at September 30, 2020 and December 31, 2019, 71,078,958 shares issued and outstanding at September 30, 2020 and 58,090,233 shares issued and outstanding at December 31, 2019	71,079	58,090
Additional paid-in-capital	203,021,404	194,234,151
Accumulated other comprehensive income (loss)	6,727	(4,964)
Accumulated deficit	(186,897,880)	(170,317,643)
Total stockholders’ equity	16,201,354	23,969,634
Total liabilities and stockholders' equity	$ 36,710,105	$ 45,119,269