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
Jehovah's Witnesses and blood transfusions who are Jehovah's Witness would not administer blood transfusions to fellow dedicated members. As to administering transfusions to non-members, "The Watchtower" stated that such a decision is "left to the Christian doctor's own conscience." In 1982, a "Watchtower" article declared that it would be wrong for a Witness to allow a leech to feed on his/her blood as part of a medical procedure, due to the sacredness of blood. In 1989 "The Watchtower" stated, "Each individual must decide" whether to accept hemodilution and autologous blood salvage (cell saver) procedures. In 1990, a brochure entitled "How Can Blood Save Your Life?"