Packed red blood cells Rh type, specifically the phenotype, and the "screen" refers to testing for atypical antibodies that might cause transfusion problems. The typing and screening are also performed on donor blood. The blood groups represent antigens on the surface of the red blood cells which might react with antibodies in the recipient. The ABO blood group system has four basic phenotypes: O, A, B, and AB. In the former Soviet Union these were called I, II, III, and IV, respectively. There are two important antigens in the system: A and B. Red cells without A or B are called type O, and
Intraoperative blood salvage As a result, the global medical community has increasingly moved from allogenic blood (blood collected from another person) towards autologous infusion, in which patients receive their own blood. Another impetus for autologous transfusion is the position of Jehovah's Witnesses on blood transfusions. For religious reasons, Jehovah's Witnesses will not accept any allogeneic transfusions from a volunteer's blood donation, but may accept the use of autologous blood salvaged during surgery to restore their blood volume and homeostasis during the course of an operation, although not autologous blood donated beforehand. There are other religious/ non-religious individuals besides Jehovah's Witnesses that accept Intraoperative