Consolidated Balance Sheets - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 22,397,812	$ 7,619,748
Short-term investments available-for-sale, at fair value	6,298,075	25,410,222
Restricted cash		3,270,247
Accounts receivable	1,588,767	3,164,176
Inventory, net of allowance of $26,052 at December 31, 2020 and $39,403 at December 31, 2019	1,492,126	1,269,667
Prepaid expenses and other	1,094,273	633,522
Total current assets	32,871,053	41,367,582
Operating lease right-of-use assets	1,009,097	1,209,145
Property and equipment, net	1,227,402	2,240,133
Other non-current assets	90,356	302,409
Total assets	35,197,908	45,119,269
Current liabilities:
Accounts payable	1,348,762	1,662,583
Accrued liabilities	1,459,878	1,870,296
Contract liabilities - current	185,083	426,014
NuvoGen obligation - current	512,729	1,152,233
Current portion of long-term debt, net	3,022,139	2,987,667
Operating lease liabilities - current	685,220	758,932
Other current liabilities	22,563	41,134
Total current liabilities	7,236,374	8,898,859
NuvoGen obligation - non-current, net of discount	4,479,396	4,498,777
Long-term debt, net of current portion and discount and debt issuance costs	8,568,308	6,871,545
Operating lease liabilities - non-current	368,682	636,340
Other non-current liabilities	60,488	244,114
Total liabilities	20,713,248	21,149,635
Commitments and Contingencies (Note 15)
Stockholders’ equity:
Series A convertible preferred stock, $0.001 par value; 23,770 shares authorized, issued and outstanding at December 31, 2020 and no shares authorized, issued or outstanding at December 31, 2019	24
Common stock, $0.001 par value; 26,666,667 shares authorized at December 31, 2020 and December 31, 2019, 5,199,997 shares issued and outstanding at December 31, 2020 and 3,872,682 shares issued and outstanding at December 31, 2019	5,200	3,873
Additional paid-in-capital	205,661,999	194,288,368
Accumulated other comprehensive income (loss)	5,298	(4,964)
Accumulated deficit	(191,187,861)	(170,317,643)
Total stockholders’ equity	14,484,660	23,969,634
Total liabilities and stockholders' equity	$ 35,197,908	$ 45,119,269