1. 1 BacTx ™ Kit for Detection of Bacterial Contamination of Platelets Andrew E. Levin, Ph.D. Immunetics, Inc. Blood Products Advisory Council Meeting March 9, 2006

2. 2 BacTx ™ Kit for Detection of Bacterial Contamination of Platelet Units

3. 3 BacTx ™ Kit Features R&D supported by NHLBI grant HL065877  < 1 hour turnaround time  1 ml sample volume  Premeasured vial reagent dispensing  Detects both gram positives and gram negatives  10 3 – 10 4 CFU/ml assay sensitivity  < 10 CFU/ml detected at 24 hrs post platelet collection  Absorbance readout = result record

4. 4 Bacterial Peptidoglycan Cell Wall NAM NAG Peptide bridge NAG = N-Acetyl Glucosamine NAM = N-Acetyl Muramic Acid

5. 5 BacTx ™ Assay Target: Peptidoglycan Peptidoglycan – universal component of bacterial cell wall – both gram positive and gram negative species Common molecular structure recognized by peptidoglycan binding protein

6. 6 BacTx ™ Assay Technology Peptidoglycan Peptidoglycan binding protein (PGBP) Enzyme Chromogen Binding of PGBP to peptidoglycan triggers enzymatic conversion of chromogenic substrate to visible product with measurable absorbance

7. 7 BacTx ™ Assay Format Spin down, extract Incubate 30 min Platelet Unit Results 1 ml 10 min Read Absorbance Sample 1234

8. 8 Assay dose-response curve: Bacteria spiked into platelets 35,00018,000 3,5001,800 350180 3518 00 CFU/ml

9. 9 AABB 2004 Abstract #SP47 E. coliP. aeruginosaS. epidermidis S. marcescensPurified peptidoglycan 500025001250625 313 156 NegPos 500025001250625 313 156 NegPos500025001250625 313 156 NegPos 500025001250625 313 156 NegPos10.05.02.501.25 0.62 0.31 0.16 0 CFU/ml ng/ml BacTx ™ Sensitivity for Gram Positive and Negative Bacteria

10. 10 Time course of detection of Staph. epidermidis spiked at 10 CFU/ml into platelet bag AABB 2004 Abstract #SP47 Earliest detection < 7 hours post-inoculation

11. 11 P. aeruginosa S. epidermidis S. marcescens Time to detection (hours) BacTx TM S. aureus Automated Culture BacTx TM Time to detection 10 3 -10 4 CFU/ml BacTx ™ vs. BacT/ALERT AABB 2005 Abstract #SP74 BacTx TM 8 hours

12. 12 Time to Detection: BacTx ™ vs. BacT/ALERT AABB 2005 Abstract #SP74 100% concordance Inoculum BacT/ALERTBacTx™ 24 hrs 48 hrs 0 hrs Time after inoculation:

13. 13 0% 100% Automated culture Pall BDS or Bact/ALERT BacTx ™ n=45 13 SDP, 25 RDP, 7 Non-LR RDP Pos Neg PosNeg 100% Concordance BacTx ™ vs. Culture: Testing Pre-screened Negative Units

14. 14 Apheresis vs Random Donor units Units inoculated at ~10 CFU/ml, sampled for assay at 48 hours CFU/ml @ 48 hrs 003.6 x 10 8 6x 10 7 8x 10 7 7x 10 8 5x 10 7 9x 10 7 Equivalent performance in BacTx TM assay

15. 15 Thank you Andrew Levin Immunetics, Inc. 27 Drydock Ave. Boston, MA 02210 Tel. 617-896-9100 alevin@immunetics.com R&D supported by NHLBI grant HL065877