Stock Award Plans (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Based Award Plans

The following table summarizes information about the Company’s stock-based award plans as of December 31, 2021:

	Outstanding Options		Outstanding Restricted Stock Units		Shares Available for Future Issuance
2004 Equity Incentive Plan		206,358		—		—
2013 Equity Incentive Plan		3,639,936		2,600		—
2018 Equity Incentive Plan		6,800,852		7,606,425		5,344,810
2004 Non-Employee Directors’ Stock Option Plan		8,000		—		—
Total		10,655,146		7,609,025		5,344,810

Stock Based Compensation Expense Recognized in Accompanying Consolidated Statements of Operations by Category

Total stock-based compensation expense recognized in the accompanying consolidated statements of operations is included in the following categories (in thousands):

	Year Ended December 31,
	2021		2020
Cost of goods sold	$	407	$	446
Cost of revenue — collaborations and services		1,708		626
Research and development		614		338
Selling, general and administrative		9,471		5,101
Total	$	12,200	$	6,511

Assumptions Used to Calculate Fair Value of Employee Stock Options

The Company calculated the fair value of employee stock options granted during the year ended December 31, 2020 using the following assumptions:

	Year Ended December 31,
	2020
Risk-free interest rate	0.39% — 1.52%
Expected lives	5.67 — 7.0 years
Volatility	93.83% — 94.25%
Dividends		—

Summary of Stock Options Outstanding

The following table summarizes information relating to stock options:

	Number of Shares			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value ($000)
Outstanding at January 1, 2021		12,264,616		$	3.41		6.45	$	15,414
Granted		—			—
Exercised		(586,572	)		1.72
Forfeited		(258,410	)		1.59
Expired		(764,488	)		11.57
Outstanding at December 31, 2021		10,655,146		$	2.96		5.82	$	25,458
Exercisable at December 31, 2021		8,009,961		$	3.40		5.58	$	18,436

Summary of Restricted Stock Unit Activity

The following table summarizes information relating to restricted stock units:

	Number of Shares			Weighted Average Grant Date Fair Value per Share
Outstanding at January 1, 2021		6,037,542		$	2.20
Granted		3,326,798			5.82
Vested		(1,516,065	)		2.22
Forfeited		(239,250	)		2.58
Outstanding at December 31, 2021		7,609,025			3.77