Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (6,497,519)	$ (4,848,307)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	185,492	197,951
Accretion of discount on NuvoGen obligation	(2,983)	(3,106)
Provision for excess inventory	59,353	4,836
Amortization of SVB Term Loan discount and issuance costs	117,727	123,010
Stock-based compensation expense	251,214	337,824
Employee stock purchase plan expense	16,591	13,115
Non-cash operating lease expense	100,316	151,831
Accrued interest on available-for-sale securities investments	(5,128)	(3,600)
Loss on abandonment and disposal of assets, net		178,925
Changes in operating assets and liabilities:
Accounts receivable	1,343,246	56,997
Inventory	(120,164)	(115,584)
Prepaid expenses and other	93,299	(401,597)
Accounts payable	(352,934)	145,309
Accrued liabilities	(1,069,543)	(336,973)
Contract liabilities	40,279	302,357
Operating lease liabilities	(98,809)	(156,249)
Net cash used in operating activities	(5,939,563)	(4,353,261)
Investing activities
Purchase of property and equipment	(8,415)	(98,509)
Maturities of available-for-sale securities	5,400,000	6,300,000
Purchase of available-for-sale securities		(8,986,169)
Net cash (used in) provided by investing activities	5,391,585	(2,784,678)
Financing activities
Proceeds from ATM Offering, net of commissions of $0.2 million		6,855,198
Proceeds from March 2022 Purchase Agreement, net of $0.4 million of issuance costs	7,207,499
Payments on NuvoGen obligation	(172,624)	(154,777)
Payments on SVB Term Loan	(1,250,000)
Payments on deferred offering costs	(38,500)
Payments on financing leases	(4,635)	(6,905)
Proceeds from exercise of stock options		326
Taxes paid for net share settlement of restricted stock awards	(8,129)	(1,197)
Payments on insurance notes	(167,586)	(165,099)
Net cash provided by financing activities	5,566,025	6,527,546
Effect of exchange rates on cash	(3,570)	(9,732)
Increase (decrease) in cash and cash equivalents	5,014,477	(620,125)
Cash and cash equivalents at beginning of period	9,599,950	22,397,812
Cash and cash equivalents at end of period	14,614,427	21,777,687
Supplemental disclosure of noncash investing and financing activities
Fixed asset purchases payable and accrued at period end		10,738
Issuance of common stock upon conversion of Series A convertible preferred stock	1,402,430
Deferred financing costs payable and accrued at period end	98,713
Supplemental cash flow information
Cash paid for interest	$ 139,846	146,161
Cash paid for taxes		$ 90