The Company and a Summary of its Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Schedule of Revenues Disaggregated by Revenue Source

The following table presents the Company’s revenues disaggregated by revenue source during the three and nine months ended September 30, 2020 and 2019 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Assay Revenue
PLA test	$	1,233	$	385	$	2,678	$	905
Contract Revenue
Adhesive patch kits		67		101		106		436
RNA extractions		—		—		764		200
Project management fees		62		79		216		232
Other		—		—		—		2
Total revenues	$	1,362	$	565	$	3,764	$	1,775

Assumptions Used to Estimate Fair Value of Each Option for Employees on Date of Grant

The fair value of each option for employees was estimated on the date of grant using the following assumptions:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Assumed risk-free interest rate	0.36%		1.68%		0.36% - 1.69%		1.68% - 2.50%
Assumed volatility	71.41%		73.50%		64.03% - 71.41%		73.20% - 73.50%
Expected option term	6.05 - 6.16		6.02		5.04 - 6.25		6.02 - 6.08
Expected dividend yield		—		—		—		—

Summary of Assets Measured at Fair Value on Recurring Basis

The following table provides a summary of the assets that are measured at fair value on a recurring basis as of September 30, 2020 (in thousands):

	September 30, 2020
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents	$	3,077	$	—	$	—	$	3,077
Marketable securities, available for sale:
Corporate debt		—		7,960		—		7,960
Municipal securities		—		6,804		—		6,804
U.S. government debt securities		—		22,143		—		22,143
Total marketable securities, available for sale		—		36,907		—		36,907
Total assets measured at fair value on a recurring basis	$	3,077	$	36,907	$	—	$	39,984