This SBIR Phase I project is focused on developing a new method for inactivating bacteria in human blood platelet products. thereby improving safety and extending product shelf life. Currently, standard practice in the U.S. is to discard unused platelets after five days to reduce the risk of bacterial contamination. Even with present safeguards, it has been estimated that as many as 1% of platelet infusions are contaminated with bacteria that cause sepsis in the patient, sometimes resulting in death. Preliminary measurements performed by an independent laboratory indicate that Science Research Laboratory's proprietary process shows promise for addressing these problems. Phase I experiments will determine how well SRL's process reduces the number of bacteria to a safe level in stored platelets and how well the platelets survive. This process would have several beneficial applications. The immediate benefit would be to reduce the number of illnesses and deaths caused by bacteria. A further benefit would be the possible extension of the shelf life of platelet products. Phase I will determine the efficacy of this method. Phase II will include the engineering design of a complete system that can be commercialized and the testing of this method in laboratory animals. PROPOSED COMMERCIAL APPLICATIONS: The commercial application for this research will be the inactivation of bacteria in platelet products that are stored in blood banks in the U.S., thereby reducing the number of transfusion-induced illnesses and deaths. Another benefit may be the possible extension of platelet storage time from 5 days to 7 days, thereby reducing collection and disposal costs; this would result in net savings of more than $70 million dollars annually, in the U.S. alone.