Plasma of rats infected with Trypanosoma evansi contained soluble antigen detected by the agar diffusion method. The antigen protected mice against homologous challenge but was not agglutinogenic. Whether the two properties were due to one or two antigens, respectively, was not ascertained. Trypanosome homogenate contained three antigens, two of which were exclusive to the trypanosome, whereas the third antigen was the same as the soluble antigen of the infected rat plasma as established by the gel diffusion and indirect haemagglutination tests.
GillB. S.1964; Indirect haemagglutination technique in the study of experimental Trypanosoma evansi infections. Ann. trop. Med. Parasit 58: (in the Press)