Precipitation test for infectious mononucleosis and enterovirus diseases.

An extract of bovine kidney obtained by trypsin digestion was used in double diffusion gel precipitation tests. Positive results were obtained with seven of twenty-seven infectious mononucleosis sera, five of twenty-five sera of patients with enterovirus diseases, and with only two of sixty normal human sera. The precipitating factor was unrelated to heterophile antibodies detectable by sheep cell haemagglutination and ox cell haemolysis. On the other hand, the precipitating factor appeared to be closely related to the serum factor previously demonstrated by mixed agglutination reactions with bovine kidney cell cultures.