CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities
Net loss	$ (15,917)	$ (16,982)	$ (16,911)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	744	922	853
Stock-based compensation	2,541	1,850	1,828
Changes in revaluation of warrant liability	(2,059)	(486)	(39)
Gain on non-controlling equity interest	0	0	(315)
Non-cash interest expense	20	5	152
Deferred income taxes	62	0	0
Changes in operating assets and liabilities, net of effects of acquired business:
Accounts receivable	1,652	(1,304)	(1,167)
Inventories	(3,740)	(601)	2,066
Other assets	(1,663)	(13)	99
Accounts payable	2,506	1,450	(1,193)
Accrued restructuring	0	0	(113)
Accrued liabilities	1,971	(336)	569
Deferred revenue	(34)	(137)	(97)
Net cash used in operating activities	(13,917)	(15,632)	(14,268)
Investing activities
Purchases of furniture, equipment and leasehold improvements	(81)	(158)	(1,692)
Sales (purchases) of certain other assets	(1)	55	(11)
Sales of investments	0	0	88
Maturities of investments	287	666	1,545
Net cash provided by (used in) investing activities	205	563	(70)
Financing activities
Net proceeds from equity incentives and the exercise of warrants	332	143	370
Net proceeds from public offering	14,226	9,273	19,291
Proceeds from landlord provided leasehold incentives	0	0	1,561
Proceeds from revolving line of credit	1,810	2,300	0
Proceeds from debt, net of discount	0	4,910	4,811
Payments on revolving line of credit	(920)	0	0
Payments on debt and landlord provided leasehold incentives	(537)	(5,008)	(34)
Net cash provided by financing activities	14,911	11,618	25,999
Net increase (decrease) in cash and cash equivalents	1,199	(3,451)	11,661
Cash and cash equivalents, beginning of period	25,497	28,948	17,287
Cash and cash equivalents, end of period	26,696	25,497	28,948
Supplemental disclosures:
Non-cash conversion of preferred stock to common stock	9,496	0	0
Common stock issued in connection with the acquisition of certain assets of BioOne	0	0	3,423
Cash paid for interest	460	1,024	600
Cash paid for income taxes	$ 162	$ 125	$ 114