 Previously stored Test and fresh Control platelets will be radiolabeled according to randomization assignment with either Chromium-51 51Cr 20 μCi as sodium radiochromate Na251CrO4 or Indium-111 111In 15 μCi as indium oxine, following the labeling and washing procedures outlined by the Biomedical Excellence for Safer Transfusion BEST Collaborative. The isotope labels will be assigned randomly with equal probability that fresh platelets and stored INTERCEPT Blood System for platelets will be labeled with each isotope., and the same randomization assignment of isotope labels will be utilized for both donation periods for the same subject. Aliquots of the fresh and stored platelets will be radiolabeled in tubes with the standard techniques. After radiolabeling, the autologous fresh and stored INTERCEPT Blood System for platelets will be simultaneously infused into the subject approximately 10-30 mL. Negative pregnancy test for females of childbearing potential are required before infusion. 