Infectious Mononucleosis (I.M.) Test

The IM test is used for the qualitative screening and semi-quantitative determination of heterophile antibodies in serum as an aid in the diagnosis of infectious mononucleosis. IM occurs most often in individuals 15-30 years of age. There are few to no symptoms but is highly contagious.

The IM test provides a suspension of polystyrene latex particles which have been coated with partially purified glycoprotein from bovine red blood cells. The heterophile antibody associated with IM binds to the corresponding antigenic determinants on the glycoprotein coated latex. This binding is evident by rapid agglutination of the latex. As a result of the purification of the bovine red cell glycoprotein, the coated latex particles are not agglutinated by Forssman or Serum Sickness antibodies at levels normally encountered. Thus, no differential absorption is required.