The process of apheresis involves removal of whole blood from a donor. Within an instrument that is essentially designed as a centrifuge, the components of whole blood are separated. One of the separated portions is then withdrawn, and the remaining components are retransfused into the donor. Directed donation is collected from a blood donor other than the recipient, but the donor is known to the recipient and is usually a family member or friend. Autologous donation is the collection and reinfusion of the patient’s own blood. Allogeneic donation is collected from a blood donor other than the recipient.