Neutralization of P blood group antibodies by synthetic solid‐phase antigens

P blood group system antibodies are encountered frequently in clinical transfusion practice. The authors describe an improved method for removing P antibodies from patient specimens without dilution. Solid-phase synthetic P antigens were used to neutralize serums containing P blood group system antibodies; 26 alloantibodies with specificity other than P were not inhibited. The synthetic P antigens are also used to characterize the heterogeneous immunochemical fine specificity of antibodies to P1 and P + P1 + Pk.