Balance Sheets - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 12,462,872	$ 9,221,985
Accounts receivable, net of allowances of $90,111 and $39,966 at December 31, 2015 and 2014, respectively	742,714	580,240
Inventories	1,089,084	679,740
Prepaid expenses and other current assets	852,600	608,160
Total current assets	15,147,270	11,090,125
Fixed assets, net	683,534	311,520
Other long-term assets	203,686	585
Total assets	16,034,490	11,402,230
Current liabilities:
Accounts payable	1,060,135	522,871
Accrued compensation	848,689	885,353
Accrued expenses	1,055,483	1,264,876
Current portion of deferred revenue	227,172	25,048
Total current liabilities	3,191,479	2,698,148
Deferred revenue, net of current portion	0	9,635
Common stock warrants	280,303	5,307,332
Total liabilities	$ 3,471,782	$ 8,015,115
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock	$ 0	$ 0
Common stock, $0.0001 par value; 100,000,000 and 50,000,000 authorized at December 31, 2015 and 2014, respectively; 4,047,332 and 2,038,151 shares issued and outstanding at December 31, 2015 and 2014, respectively	405	204
Additional paid-in capital	176,127,932	157,765,209
Accumulated deficit	(163,565,650)	(154,378,302)
Total stockholders’ equity	12,562,708	3,387,115
Total liabilities and stockholders’ equity	16,034,490	11,402,230
Series A Convertible Preferred Stock
Stockholders’ equity:
Preferred stock	0	4
Series B Convertible Preferred Stock
Stockholders’ equity:
Preferred stock	7	0
Series C Convertible Preferred Stock
Stockholders’ equity:
Preferred stock	$ 14	$ 0