Blood Collection, Processing, and Component Storage
Donor qualification
Donors must meet age requirements (generally 16-17 years and older per state and FDA rules), weigh at least 50 kg, have hemoglobin at least 12.5 g/dL (female) or 13.0 g/dL (male), and have acceptable vital signs (oral temperature 37.5 C or less, blood pressure 180/100 or less, pulse 50-100). Whole-blood donors must wait 8 weeks between donations; a 450-500 mL collection plus samples is standard, within 10 percent of the labeled volume.
Anticoagulants and storage
CPD, CP2D, and CPDA-1 support 21-day red cell storage; additive solutions (AS-1, AS-3, AS-5, SAG-M) extend storage to 42 days at 1-6 C. Storage lesion includes falling 2,3-DPG and ATP, falling pH, rising potassium and lactate, and progressive hemolysis. Irradiated red cells expire 28 days after irradiation or on the original expiration date, whichever is sooner. Washed and deglycerolized units expire in 24 hours at 1-6 C. Prestorage leukoreduction reduces white cells below 5 x 10^6 per unit and prevents febrile reactions, CMV transmission, and HLA alloimmunization.
Platelets from whole blood are pooled (typically 4-6 units, at least 5.5 x 10^10 per unit); apheresis platelets contain at least 3 x 10^11. Both are stored at 20-24 C with continuous agitation for 5 days; bacterial contamination is the main residual infectious risk, addressed by culture about 24 hours after collection and rapid tests. Plasma is frozen within 8 hours (FFP) or 24 hours (FP24), stored at -18 C or colder for one year, and after thawing used within 24 hours, or relabeled as thawed plasma for 5 days at 1-6 C. Cryoprecipitate is made by thawing FFP at 1-6 C, contains at least 80 IU factor VIII and 150 mg fibrinogen per unit, and after thawing must be used within 4-6 hours (4 hours pooled).
Traps
Confusing post-irradiation expiry (28 days) with post-wash expiry (24 hours), refrigerating platelets, and forgetting that plasma requires -18 C or colder.
Rule of thumb: red cells cold (1-6 C), platelets warm with agitation (20-24 C), plasma frozen (-18 C or colder).