orm antibodies against the H antigen present on all red blood cells.[26][27]Blood donors with particularly strong anti-A, anti-B or any atypical blood group antibody are excluded from blood donation. The possible reactions of anti-A and anti-B antibodies present in the transfused blood to the recipient's RBCs need not be considered, because a relatively small volume of plasma containing antibodies is transfused.By way of example: considering the transfusion of O Rh D negative blood (universal donor blood) into a recipient of blood group A Rh D positive, an immune reaction between the recipient's anti-B antibodies and the transfused RBCs is not anticipated. However, the relatively small amount of plasma in the transfused blood contains anti-A antibodies, which could react with the A antigens on the surface of the recipients RBCs, but a significant reaction is unlikely because of the dilution factors.  Rh D sensitization is not anticipated.Additionally, red blood cell surface antigens