WHAT IS MONOSPOT SCREEN (HETEROPHIL SCREEN) TEST?
The monospot screen, a screening test that rapidly detects heterophil agglutinins, is performed on two slides, each containing serum and red horse cells, with one slide also containing guinea pig kidney and the other slide containing beef red cell stroma. Agglutination that occurs on only the slide with guinea pig kidney is diagnostic of infectious mononucleosis. Heterophil agglutinins can appear in serum approximately 6-10 days after contact. Detection may remain for up to 1 year and peaks between 4 and 8 weeks after exposure.