[Antigen analysis of Toxoplasma gondii using chromatography, polyacrylamide gel electrophoresis and immunoprecipitation].

Whole (EAT), cytoplasmic (EAC) and membranous (EAM) extracts were prepared from Toxoplasma gondii RH Strain trophozoites by means of osmotic lysis and/or ultra sonication. Sephacryl S 300 gel chromatography shows respectively 5, 4 and 2 protein fractions from EAT, EAC and EAM. Polyacrylamide gel electrophoresis (PAGE) allowed to detect 22 proteins (WM from 6 to 130 Kd) from cytoplasmic extract and 3 proteins (MW: 8, 30 and 65 Kd) from membranous extract. Immunoprecipitation techniques were performed with polyclonal antibodies against Toxoplasma prepared from serum and rabbits immunized with EAT. Counter electro-immunodiffusion (CEID) on cellulose acetate membrane was found to be more sensitive than double immunodiffusion and immunoelectrophoresis as it detected 8 lines with both cytoplasmic and membranous extracts. The latter seem to be composed of large numbers of proteins which are present in very low quantities difficult to detect in PAGE, but very antigenic and easily shown by CEID.