Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Product revenue	$ 176	$ 2,098	$ 2,312	$ 4,377
Contract revenue	128	515	483	1,261
Development revenue	660	0	1,840	0
Total revenue	964	2,613	4,635	5,638
Cost of product revenue	8	887	1,509	4,781
Cost of contract revenue	76	251	239	654
Total cost of revenue	84	1,138	1,748	5,435
Gross margin	880	1,475	2,887	203
Research and development expense	2,893	3,097	7,484	10,264
Sales, marketing, general and administrative expense	2,132	2,425	6,636	8,777
Gain on disposal of fixed assets	(33)	(46)	(35)	(47)
Total operating expenses	4,992	5,476	14,085	18,994
Loss from operations	(4,112)	(4,001)	(11,198)	(18,791)
Change in warrant liability	397	0	397	0
Other income (expense)	48	156	44	172
Net loss	$ (3,667)	$ (3,845)	$ (10,757)	$ (18,619)
Net loss per share - basic and diluted	$ (0.13)	$ (0.15)	$ (0.40)	$ (0.91)
Weighted-average shares outstanding - basic and diluted	28,448	24,974	26,739	20,406