Balance Sheet Details (Tables)

12 Months Ended

Dec. 31, 2022

Balance Sheet Related Disclosures [Abstract]

Schedule of Cash and Cash Equivalents

Cash equivalents consisted of the following (in thousands): 

	December 31, 2022				December 31, 2021
	Adjusted Cost		Estimated Fair Value		Adjusted Cost		Estimated Fair Value
Money market funds (1)	$	77,309	$	77,309	$	86,095	$	86,095

(1) Money market funds are classified in cash and cash equivalents on our consolidated balance sheets. Average contractual maturities (in days) is not applicable.

Schedule of Inventory Components

Inventories consisted of the following (in thousands): 

	December 31,
	2022		2021
Raw materials	$	108	$	49
Work in process	91		65
Finished goods	1,830		1,046
Total inventories	$	2,029	$	1,160

Property and Equipment, Net

Property, equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization calculated using the straight-line method over their estimated useful lives as follows:

Asset classification	Estimated useful life
Laboratory equipment	5 years
Computer equipment and software	3 to 5 years
Office equipment and furniture	5 years
Leasehold improvements	Lesser of useful life or lease term

Property and equipment, net consisted of the following (in thousands): 

	December 31,
	2022		2021
Laboratory equipment (1)	$	39,679	$	33,101
Leasehold improvements	16,633		16,117
Computer equipment and software	3,039		3,481
Office equipment and furniture	1,345		1,297
Construction in progress (2)	1,739		3,231
Property and equipment	62,435		57,227
Less: accumulated depreciation and amortization	(39,821)		(35,882)
Property and equipment, net	$	22,614	$	21,345

(1) Fully depreciated property and equipment with a cost of $1.5 million and $0.6 million were retired during the years ended December 31, 2022 and 2021, respectively.

(2) Construction in progress includes equipment received but not yet placed into service pending installation.

Depreciation expense included in both research and development expenses and selling, general and administrative expenses in the consolidated statements of operations was as follows (in thousands):

	Year Ended December 31,
	2022		2021		2020
Depreciation expense	$	5,402	$	3,113	$	1,950

Schedule of Accrued Liabilities

Other accrued liabilities consisted of the following (in thousands): 

	December 31,
	2022		2021
Accrued purchases	$	10,852	$	6,755
Accrued professional and outside service fees	3,495		5,147
Other	932		676
Total other accrued liabilities	$	15,279	$	12,578