Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue:
Product and service	$ 19,167	$ 13,910	$ 48,791	$ 37,240
Collaboration	4,766	1,783	12,466	3,112
Total revenue	23,933	15,693	61,257	40,352
Costs and expenses:
Cost of product and service revenue	8,075	6,289	21,816	17,500
Research and development	8,717	5,812	24,724	17,526
Selling, general and administrative	15,607	12,036	46,018	38,984
Total costs and expenses	32,399	24,137	92,558	74,010
Loss from operations	(8,466)	(8,444)	(31,301)	(33,658)
Other income (expense):
Interest income	104	58	266	181
Interest expense	(1,509)	(1,022)	(4,150)	(3,007)
Other income (expense), net	(179)	(59)	(238)	(281)
Total other income (expense), net	(1,584)	(1,023)	(4,122)	(3,107)
Net loss before provision for income tax	(10,050)	(9,467)	(35,423)	(36,765)
Provision for income tax	(38)	0	(73)	0
Net loss	$ (10,088)	$ (9,467)	$ (35,496)	$ (36,765)
Net loss per share - basic and diluted (in dollars per share)	$ (0.51)	$ (0.49)	$ (1.79)	$ (1.95)
Weighted average shares used in computing basic and diluted net loss per share (in shares)		19,431	19,779	18,862