Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net loss	$ (57,688)	$ (31,530)	$ (40,796)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	4,851	4,312	3,009
Inventory step-up amortization	275	722	611
Credit loss expense on accounts receivable	213	493	160
Reduction in the carrying amounts of right-of-use assets	499	245
Stock-based compensation expense	15,975	10,099	6,388
Non-cash interest expense	65	86	89
Loss on disposal of fixed assets	89	171	140
Changes in operating assets and liabilities:
Accounts receivable	(6,853)	(6,733)	(3,525)
Prepaid expenses and other assets	(393)	(3,927)	289
Inventory	(8,090)	(5,119)	(3,447)
Other non-current assets	(2)	198	(21)
Accounts payable	2,414	649	621
Accrued compensation and benefits, other accrued expenses and other current liabilities	1,061	6,219	822
Contract acquisition costs	(192)	87	336
Operating lease liabilities	(1,230)	316
Other non-current liabilities	(363)	(488)	9,845
Deferred revenue	1,462	835	(708)
Net cash used in operating activities	(47,907)	(23,365)	(26,187)
Investing activities
Purchases of property and equipment	(13,616)	(3,930)	(10,847)
Acquisitions, net of cash acquired			(14,529)
Proceeds from RADx grant on assets purchased	7,278	3,304
Net cash used in investing activities	(6,338)	(626)	(25,376)
Financing activities
Proceeds from stock options exercised	7,750	4,019	2,820
Proceeds from ESPP purchase	1,065	888	879
Payments on notes payable	(7,738)	(75)	(50)
Net cash provided by financing activities	270,795	96,236	116,197
Net increase in cash and cash equivalents	216,550	72,245	64,634
Effect of foreign currency exchange rate on cash	(92)	158	118
Cash, restricted cash, and cash equivalents at beginning of period	182,584	110,181	45,429
Cash, restricted cash, and cash equivalents at end of period	399,042	182,584	110,181
Supplemental cash flow information
Cash paid for interest	389	625	656
Purchases of property and equipment included in accounts payable and other accrued expenses	229	1,029	164
Purchase of property and equipment included in other non-current liabilities			7,572
Common stock issued in connection with the acquisition of UmanDiagnostics AB			5,468
At-the-market offering.
Financing activities
Sale of common stock			48,019
Underwritten public offering
Financing activities
Sale of common stock	$ 269,718	$ 91,404	$ 64,529