Antibody identification

Process of determining which antibody is causing a positive antibody screen ordered for a patient who may need a blood transfusion. After an antibody screen (IAT or indirect antiglobulin test) is found to be positive (i.e., causes agglutination), antibody identification is conducted to determine whether the offending antibody is an alloantibody, autoantibody, or both. Reagent red blood cells with known phenotypes are tested with the patient's serum as well an an autocontrol, and the presence of agglutination is noted. The panels are interpreted by a blood bank technician or technologist or pathologist and the identified antibody is recorded in the patient's medical record. If a transfusion is required, compatible blood is supplied based on those results.