CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 36,286,000	$ 26,754,000
Short-term marketable securities	8,882,000	45,236,000
Accounts receivable, net of allowances of $75 and $2,754, respectively	11,534,000	10,676,000
Inventories	10,244,000	10,949,000
Prepaid expenses and other current assets	1,483,000	2,216,000
Total current assets	68,429,000	95,831,000
Property and equipment, net	21,070,000	22,581,000
Intangible assets, net	2,023,000	2,624,000
Restricted cash	758,000	758,000
Other long-term assets	701,000	505,000
Total assets	92,981,000	122,299,000
Current liabilities
Accounts payable	9,886,000	11,171,000
Accrued compensation	7,358,000	5,419,000
Current portion of long-term debt	0	7,927,000
Other current liabilities	3,043,000	3,226,000
Total current liabilities	20,287,000	27,743,000
Long-term liabilities
Deferred rent	2,996,000	3,059,000
Long-term debt	36,042,000	20,099,000
Other noncurrent liabilities	109,000	241,000
Total liabilities	59,434,000	51,142,000
Commitments and contingencies - See Note 7
Stockholders' equity
Preferred stock, $0.0001 par value; 5,000 authorized, none issued	0	0
Common stock, $0.0001 par value; 100,000 authorized; 56,240 and 55,066 shares issued and outstanding, respectively	6,000	6,000
Additional paid-in capital	500,344,000	487,525,000
Accumulated deficit	(466,883,000)	(416,383,000)
Accumulated other comprehensive income	80,000	9,000
Total stockholders’ equity	33,547,000	71,157,000
Total liabilities and stockholders’ equity	$ 92,981,000	$ 122,299,000