Cold Apheresis Platelets in PAS

Inclusion Criteria: * Weight: ≥ 110 pounds * Platelet count: ≥ 150X10\^3/mL * Hematocrit: 38% for females, 39% for males, but not \>55% * Temperature: ≤ 99.5 F * Resting blood pressure: systolic ≤180 mmHg; diastolic ≤ 100 mmHg * Resting heart rate: 40 to 100 beats per minute * Subjects must be: at least 18 years old, of either sex * Subjects must be able to read, understand and sign the informed consent document and commit to the study follow-up schedule. The ability to read and speak English is required for participation. * Subjects must have good veins for apheresis platelet collection and drawing blood samples. * Subjects of child-bearing potential (either male or female) must agree to use an effective method of contraception during the course of the study. The following methods of contraception are be considered effective; abstinence, intrauterine contraception devices, hormonal methods, barrier methods or history of sterilization. Exclusion Criteria: Healthy subjects will be excluded from the study for any of the following reasons: * Unable to achieve target platelet yield of 3.0 X 1011/unit per Trima Accel (apheresis machine) configuration parameters. * Ever received radiation therapy. * Already participated in 4 research studies involving radioisotopes within the contemporaneous calendar-year. * Taken aspirin, non-steroidal anti-inflammatory, or other platelet affecting drugs within 72 hours of collection or infusion. Subjects who have ever been prescribed anti-pla…