Balance Sheet Components (Details) - Property and equipment, net - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property and equipment, net [Abstract]
Laboratory equipment	$ 1,771	$ 1,565
Office and computer equipment	296	175
Leasehold improvements	281	226
Total property and equipment	2,348	1,966
Less: accumulated depreciation	(1,334)	(1,236)
Property and equipment, net	$ 1,014	$ 730

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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- Definition

Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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Laboratory equipment

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- Definition

Office and computer equipment

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