Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating activities
Net loss	$ (16,982)	$ (16,911)	$ (24,135)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	922	853	866
Stock-based compensation	1,850	1,828	2,046
Gain from revaluation of warrant liability	(486)	(39)	(63)
Loss (gain) on sale of fixed assets	(114)	46	102
Impairment of long-term investment in related party	0	0	2,340
Gain from operating settlement	0	0	(1,381)
Gain on non-controlling equity interest	0	(315)	0
Non-cash interest expense	5	152	0
Changes in operating assets and liabilities, net of effects of acquired business:
Accounts receivable	(1,304)	(1,167)	696
Inventories	(487)	2,020	3,402
Other assets	(13)	99	97
Accounts payable	1,450	(1,193)	102
Accrued restructuring	0	(113)	113
Accrued liabilities	(336)	569	1,368
Deferred revenue	(137)	(97)	(100)
Net cash used in operating activities	(15,632)	(14,268)	(14,547)
Investing activities
Purchases of furniture, equipment and leasehold improvements	(158)	(1,692)	(191)
Sales (purchases) of certain other assets	55	(11)	37
Purchases of investments	0	0	(499)
Sales of investments	0	88	499
Maturities of investments	666	1,545	9,477
Net cash provided by (used in) investing activities	563	(70)	9,323
Financing activities
Net proceeds from equity incentive plans	143	370	78
Net proceeds from public offering	9,273	19,291	12,135
Proceeds from landlord provided leasehold incentives	0	1,561	0
Proceeds from revolving line of credit	2,300	0	0
Proceeds from debt, net of discount	4,910	4,811	0
Payments on debt and landlord provided leasehold incentives	(5,008)	(34)	(5)
Net cash provided by financing activities	11,618	25,999	12,208
Net increase (decrease) in cash and cash equivalents	(3,451)	11,661	6,984
Cash and cash equivalents, beginning of period	28,948	17,287	10,303
Cash and cash equivalents, end of period	25,497	28,948	17,287
Supplemental disclosures:
Common stock issued in connection with the acquisition of certain assets of BioOne	0	3,423	0
Cash paid for interest	$ 1,024	$ 600	$ 4