The compatibility of the blood from the donor with that of the recipient must be checked before a transfusion procedure. Laboratory personnel therefore carry out cross-matching tests. Antibody testing is also one of the procedures used for blood typing. The antibody tests allow the identification of irregular anti-erythrocyte antibodies that can give rise to problems in transfusions.

Before performing the tests it is first necessary to wash the erythrocytes of the donor. The erythrocytes must be free of any serum residues as these could falsify the result.