Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities
Net loss	$ (4,848,307)	$ (5,457,898)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	197,951	348,633
Accretion of discount on NuvoGen obligation	(3,106)	(3,430)
Provision for excess inventory	4,836	6,947
Amortization of QNAH Convertible Note issuance costs		3,364
Amortization of MidCap Credit Facility discount and issuance costs		42,441
Amortization of SVB Term Loan discount and issuance costs	123,010
Stock-based compensation expense	337,824	415,292
Employee stock purchase plan expense	13,115	5,379
Non-cash operating lease expense	151,831	151,726
Accrued interest on available-for-sale securities investments	(3,600)	(74,101)
Loss on abandonment and disposal of assets, net	178,925	49,226
Changes in operating assets and liabilities:
Accounts receivable	56,997	1,961,707
Inventory	(115,584)	(375,178)
Prepaid expenses and other	(401,597)	139,508
Deferred offering costs		140,320
Accounts payable	145,309	(410,806)
Accrued liabilities	(336,973)	(668,667)
Contract liabilities	302,357	(18,794)
Operating lease liabilities	(156,249)	(186,220)
Net cash used in operating activities	(4,353,261)	(3,930,551)
Investing activities
Purchase of property and equipment	(98,509)	(25,231)
Maturities of available-for-sale securities	6,300,000	8,250,000
Purchase of available-for-sale securities	(8,986,169)	(4,272,298)
Net cash provided by (used in) investing activities	(2,784,678)	3,952,471
Financing activities
Proceeds from ATM Offering, net of commissions of $0.2 million	6,855,198	2,435,912
Proceeds from Series A convertible preferred stock in private placement		600,030
Payments on NuvoGen obligation	(154,777)	(287,997)
Proceeds from exercise of pre-funded warrants		31,768
Payments on financing leases	(6,905)	(11,833)
Proceeds from exercise of stock options	326
Taxes paid for net share settlement of restricted stock awards	(1,197)	(7,052)
Payments on Insurance Note	(165,099)
Net cash provided by financing activities	6,527,546	2,760,828
Effect of exchange rates on cash	(9,732)	1,201
Increase (decrease) in cash, cash equivalents and restricted cash	(620,125)	2,783,949
Cash, cash equivalents and restricted cash at beginning of period	22,397,812	10,889,995
Cash, cash equivalents and restricted cash at end of period	21,777,687	13,673,944
Supplemental disclosure of noncash investing and financing activities
Fixed asset purchases payable and accrued at period end	10,738	289,838
Issuance of Series A convertible preferred stock in exchange for outstanding common stock		2,424,900
Series A convertible preferred stock in private placement, costs payable and accrued at period end		37,075
Issuance of common stock in connection with LP Purchase Agreement		615
LP Purchase Agreement, costs payable and accrued at period end		96,000
Supplemental cash flow information
Cash paid for interest	146,161	$ 164,005
Cash paid for taxes	$ 90