 Subjects will donate one unit of fresh whole blood. This unit will be treated with the Mirasol PRT System for whole blood and then stored for 24 hours 1 hour at 22 2C. At the end of storage, platelet concentrates will be separated from the unit according to the Biomedical Excellence for Safer Transfusion BEST procedures. An aliquot will be removed from the platelet concentrates for testing and for radiolabeling and reinfusion. The platelets in Mirasol-treated whole blood will be tested for key in vitro parameters directly after treatment Day 0 and at the end of storage Day 1. Sterility testing will also be conducted on the stored units. 