Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] |
| | 2013 | | 2012 | | | | | | | | | | Tax provision (benefit) | | | | | | | | Current | | | | | | | | Federal | | $ | | | $ | | | State | | | | | | | | Total current | | | | | | | | | | | | | | | | Deferred | | | | | | | | Federal | | | (4,705,250) | | | (3,225,486) | | State | | | 134,225 | | | 2,291,913 | | Total deferred | | | (4,571,025) | | | (933,573) | | | | | | | | | | Change in valuation allowance | | | 4,571,025 | | | 933,573 | | Total | | $ | | | $ | | |
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Schedule of Deferred Tax Assets and Liabilities [Table Text Block] |
Deferred tax assets consisted of the following at December 31:
| | 2013 | | 2012 | | | | | | | | | | Deferred tax assets | | | | | | | | Federal net operating loss | | $ | 25,731,718 | | $ | 22,343,084 | | Federal research and development tax credit carryforwards | | | 2,480,417 | | | 1,969,426 | | State net operating loss | | | 2,070,642 | | | 2,252,566 | | State research and development tax credit carryforwards | | | 724,200 | | | 633,571 | | Capitalized research and development expenses | | | 11,128,803 | | | 11,068,868 | | Stock-based compensation expense | | | 1,599,005 | | | 842,174 | | Intangible assets | | | 380,339 | | | 440,556 | | Charitable contribution carryforwards | | | 34,850 | | | 43,350 | | Accrued liabilities | | | 26,112 | | | 25,199 | | Total deferred tax assets | | | 44,176,086 | | | 39,618,794 | | | | | | | | | | Deferred tax liabilities | | | | | | | | Depreciable assets | | | (257,314) | | | (271,049) | | Total deferred tax liabilities | | | (257,314) | | | (271,049) | | | | | | | | | | Net deferred tax assets | | | 43,918,772 | | | 39,347,745 | | Less valuation allowance | | | (43,918,772) | | | (39,347,745) | | Total deferred tax assets | | $ | | | $ | | |
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