Amortized
Cost

Gross
Unrealized
Gains

Gross
Unrealized
(Losses)

Fair Value

September 30, 2012

Cash

$

281,065

$

—

$

—

$

281,065

Cash equivalents

15,431,623

—

15,431,623

Marketable debt securities, current

6,031,219

516

—

6,031,735

Total cash, cash equivalents, and marketable securities

$

21,743,907

$

516

$

—

$

21,744,423

December 31, 2011

Cash

$

291,093

$

—

$

—

$

291,093

Cash equivalents

13,020,168

—

13,020,168

Marketable debt securities, current

3,283,209

—

(2,618

)

3,280,591

Total cash, cash equivalents, and marketable securities

$

16,594,470

$

—

$

(2,618

)

$

16,591,852