| Warrant | Issue Date | Shares Issuable upon Exercise of Warrant | Exercise Price | Expiration Date | Reference | |||||||||
| Series N | 8/18/08 | 518,771 | 3.00 | 8/18/14 | 1 | |||||||||
| Series A | 6/24/09 | 130,347 | 5.00 | 12/24/14 | 1 | |||||||||
| Schleuning (Series A) | 7/8/09 | 16,750 | 5.00 | 01/8/15 | 1 | |||||||||
| Series B | 9/4/09 | 50,000 | 6.80 | 9/4/14 | 1 | |||||||||
| Series C | 8/20/09 -8/26/09 | 463,487 | 5.50 | 2/20/15 | 1 | |||||||||
| Series E | 9/21/09 | 71,428 | 17.50 | 8/12/14 | 1 | |||||||||
| Series F | 10/6/11 | 1,200,000 | 4.00 | 10/6/14 | 1 | |||||||||
| Series G | 10/6/11 | 66,667 | 4.00 | 8/12/14 | 1 | |||||||||
| Series H | 1/26/12 | 1,200,000 | 5.00 | 8/1/15 | 1 | |||||||||
| Series Q | 6/21/12 | 1,200,000 | 5.00 | 12/22/15 | 1 | |||||||||
| Series R | 12/6/12 | 2,625,000 | 4.00 | 12/6/16 | 1 | |||||||||
| Series L | 4/18/07 | 25,000 | 7.50 | 4/17/14 | 2 | |||||||||
| Series L (repriced) | 4/18/07 | 70,000 | 2.50 | 4/2/15 | 2 | |||||||||
| Series M (modified) | 4/18/07 | 600,000 | 3.40 | 7/31/14 | 2 | |||||||||
| Series P | 2/10/12 | 590,001 | 4.50 | 3/6/17 | 3 | |||||||||
| Private Investors | 7/18/05 -6/30/09 | 740,938 | 5.60 – 8.20 | 1/26/14 - 7/18/14 | 4 | |||||||||
| Warrants held by Officer and Director | 6/24/09- 7/6/09 | 349,754 | 4.00 – 5.00 | 12/24/14 - 1/6/15 | 5 | |||||||||
| Consultants | 2/15/05 – 12/28/12 | 140,750 | 2.80 – 20.00 | 5/20/14 - 12/27/17 | 6 | |||||||||