Subjects will be enrolled for evaluation of platelet recovery and survival. Healthy subjects will be consented and enrolled into the study until 8 subjects have completed the recovery and survival evaluations at 4, 8, 12, 16, and 20 days storage. The order in which storage intervals are evaluated will be randomized. Eight subjects will then be evaluated at the mid-range interval between longest storage period that meets acceptances criteria and shortest storage period that does not meet acceptance criteria. For instance, if at 12 days of storage the 95% lower confidence limits for recoveries are NOT ≥50% of fresh and survivals are LESS than one day, but at 8 days of storage recoveries are ≥50% of fresh and survivals are at least than one day, we will then evaluate 10 days of storage. If the 10 day storage does not meet acceptance criteria we will evaluate 9 days. If the 10 day storage does meet acceptance criteria we will evaluate 11 days. Eight subjects will be evaluated at each storage interval.