heterophil antibody test [Gk, heteros + philein, to love] , a test for the presence of heterophil antibodies in the serum of patients suspected of having infectious mononucleosis, based on an agglutination reaction between heterophil antibodies in a person’s serum and heterophil antigen, a normal component of sheep erythrocytes. This antibody eventually appears in the serum of more than 80% of the patients with mononucleosis caused by the Epstein-Barr virus; hence it is highly diagnostic of the disease. See also Epstein-Barr virus.
