Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenue:
Product and service	$ 10,263	$ 7,218	$ 19,014	$ 12,894
Collaboration	618		618
Total revenue	10,881	7,218	19,632	12,894
Costs and expenses:
Cost of product and service revenue	4,860	3,522	9,185	6,404
Research and development	5,274	3,626	10,006	6,685
Selling, general and administrative	12,880	6,708	23,554	12,834
Total costs and expenses	23,014	13,856	42,745	25,923
Loss from operations	(12,133)	(6,638)	(23,113)	(13,029)
Other income (expense):
Interest income	75	3	139	6
Interest expense	(2,015)	(489)	(2,551)	(874)
Other income (expense)	(15)	(9)	15	(13)
Revaluation of preferred stock warrant liability		1,638		1,156
Total other income (expense)	(1,955)	1,143	(2,397)	275
Net loss	(14,088)	(5,495)	(25,510)	(12,754)
Accretion of mandatorily redeemable convertible preferred stock		(2,311)		(4,653)
Net loss attributable to common stockholders	$ (14,088)	$ (7,806)	$ (25,510)	$ (17,407)
Net loss per share - basic and diluted	$ (0.78)	$ (13.69)	$ (1.46)	$ (31.48)
Shares used in computing basic and diluted net loss per share	18,069	570	17,496	553