Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

Benefit for Income Taxes Differs from Amount Obtained by Applying Federal Statutory Income Tax Rate to Loss before Benefit for Income Taxes

The benefit for income taxes differs from the amount obtained by applying the federal statutory income tax rate to loss before benefit for income taxes for 2014, 2013 and 2012 as follows:

	2014			2013			2012
Tax benefit computed at federal statutory rate		34.0	%		34.0	%		34.0	%
Increase (decrease) in taxes due to:
Change in valuation allowance		(37.8	)		(32.8	)		(36.8	)
Stock-based compensation		(4.0	)		(2.0	)		(3.0	)
Fair value of derivative warrant liability		2.0			(5.0	)		—
State taxes, net of federal benefit		5.8			5.8			5.8
		—	%		—	%		—	%

Significant Components of Deferred Tax Assets (Liabilities)

The significant components of deferred tax assets (liabilities) at December 31 are as follows:

	2014			2013
Loss carryforwards	$	11,490,000		$	6,910,000
Depreciation		1,490,000			1,853,000
Tax credits		388,000			103,500
Inventory		292,000			288,000
Other		280,000			394,000
Less: valuation allowance		(13,940,000	)		(9,548,500	)
	$	—		$	—