Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Product and service	$ 44,497us-gaap_SalesRevenueNet	$ 31,403us-gaap_SalesRevenueNet	$ 22,973us-gaap_SalesRevenueNet
Collaboration	3,096us-gaap_RecognitionOfDeferredRevenue	0us-gaap_RecognitionOfDeferredRevenue	0us-gaap_RecognitionOfDeferredRevenue
Total revenue	47,593us-gaap_Revenues	31,403us-gaap_Revenues	22,973us-gaap_Revenues
Costs and expenses:
Cost of product and service revenue	21,149us-gaap_CostOfRevenue	15,009us-gaap_CostOfRevenue	12,361us-gaap_CostOfRevenue
Research and development	21,404us-gaap_ResearchAndDevelopmentExpense	14,979us-gaap_ResearchAndDevelopmentExpense	11,635us-gaap_ResearchAndDevelopmentExpense
Selling, general and administrative	51,063	29,912	15,486
Total costs and expenses	93,616us-gaap_CostsAndExpenses	59,900us-gaap_CostsAndExpenses	39,482us-gaap_CostsAndExpenses
Loss from operations	(46,023)us-gaap_OperatingIncomeLoss	(28,497)us-gaap_OperatingIncomeLoss	(16,509)us-gaap_OperatingIncomeLoss
Other income (expense):
Interest income	272us-gaap_InvestmentIncomeInterest	68us-gaap_InvestmentIncomeInterest	21us-gaap_InvestmentIncomeInterest
Interest expense	(4,140)	(1,942)	(804)
Other expense	(147)us-gaap_OtherNonoperatingExpense	(66)us-gaap_OtherNonoperatingExpense	(29)us-gaap_OtherNonoperatingExpense
Revaluation of preferred stock warrant liability	0us-gaap_FairValueAdjustmentOfWarrants	1,156us-gaap_FairValueAdjustmentOfWarrants	(387)us-gaap_FairValueAdjustmentOfWarrants
Total other income (expense)	(4,015)us-gaap_NonoperatingIncomeExpense	(784)us-gaap_NonoperatingIncomeExpense	(1,199)us-gaap_NonoperatingIncomeExpense
Net loss	(50,038)us-gaap_NetIncomeLoss	(29,281)us-gaap_NetIncomeLoss	(17,708)us-gaap_NetIncomeLoss
Accretion of mandatorily redeemable convertible preferred stock	0	(4,653)	(7,533)
Net loss attributable to common stockholders	$ (50,038)	$ (33,934)	$ (25,241)
Net loss per share-basic and diluted	$ (2.80)us-gaap_EarningsPerShareBasicAndDiluted	$ (4.44)us-gaap_EarningsPerShareBasicAndDiluted	$ (71.10)us-gaap_EarningsPerShareBasicAndDiluted
Weighted average shares used in computing basic and diluted net loss per share	17,839	7,643	355

The aggregate cost of goods produced and sold and services rendered during the reporting period.

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