Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 28,451	$ 68,520
Accounts receivable (net of allowances of $356 at each of December 31, 2021 and 2020, respectively)	18,320	25,423
Inventories, net	20,825	19,689
Prepaid expenses and other current assets	4,470	4,031
Total current assets	72,066	117,663
Property and equipment, net	28,034	17,531
Operating lease right-of-use asset, net	37,119	38,114
Other non-current assets	3,689	4,680
Developed technology, net	27,927	40,206
Goodwill	106,379	106,563
Total assets	275,214	324,757
Current liabilities:
Accounts payable	10,602	9,220
Accrued compensation and related benefits	4,920	13,787
Operating lease liabilities, current	3,053	2,973
Deferred revenue, current	11,947	13,475
Deferred grant income, current	3,535	2,912
Other accrued liabilities	8,673	11,882
Advances under revolving credit agreement, current	6,838	0
Total current liabilities	49,568	54,249
Term loan, net	10,049	0
Convertible notes, net	54,160	54,224
Deferred tax liability per balance sheet	4,329	8,697
Operating lease liabilities, non-current	37,548	38,178
Deferred revenue, non-current	5,966	7,990
Deferred grant income, non-current	18,116	21,036
Other non-current liabilities	882	1,333
Total liabilities	180,618	185,707
Commitments and contingencies (Note 17)
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000 shares authorized, no shares issued and outstanding at either December 31, 2021 or 2020	0	0
Common stock: $0.001 par value, 200,000 shares authorized at December 31, 2021 and 2020; 76,919 and 74,543 shares issued and outstanding at December 31, 2021 and 2020, respectively	77	75
Additional paid-in capital	831,424	815,624
Accumulated other comprehensive loss	(907)	112
Accumulated deficit	(735,998)	(676,761)
Total stockholders’ equity	94,596	139,050
Total liabilities and stockholders’ equity	$ 275,214	$ 324,757