Use of trypsin in serologic investigation

Trypsin is an enzyme first discovered in the quest to increase the detection of newly found Rh antibodies. Because of the crude source of trypsin and challenges in its consistency in test conditions, additional enzymes and chemical treatments were devised as alternative sources to enhance the detection of antibodies. The key to successful trypsin treatment starts with reagent preparation. Optimal testing conditions should be determined with each batch of trypsin prepared. As in all enzyme treatments, quality control is required to ensure proper removal of the expected antigen(s) while not producing enzyme-specific panagglutination. Once successful quality control results have been obtained, trypsin treatment can be used to rule out "common" clinically significant alloantibodies and provide direction in the identification of antibodies to high-prevalence antigens. Trypsin treatment is a key player in the Immunohematology Reference Laboratory but is often overlooked as a tool in the Transfusion Service. If performed using the proper preparation and quality control, trypsin treatment can be a valuable tool in the serology toolkit in both settings.