title: Detection of toxoplasma IgM antibody by passive latex agglutination reaction.
abstract: Three major components (designated Sp-1, -2 and -3) of the microsomal pellet of Toxoplasma gondii (Tp) were isolated by Ultragel AcA 44 gel filtration chromatography from the microsomal pellet solubilized with detergents. Of these, Sp-2 proved to be most reactive with anti-Tp antibodies and its reactivity with IgM and IgG antibodies varied with the concentration at which it was used for sensitizing latex particles. Sp-2 antigen reacted with IgM antibody alone when latex particles were sensitized with less than or equal to 100 micrograms of this antigen/mg of particles, and its reactivity with IgG antibody appeared and increased progressively with increasing sensitizing concentrations of this antigen. Based on this finding, a method of direct measurement of anti-Tp IgM antibody in serum by passive latex agglutination has been developed. Polyacrylamide disc gel electrophoretic analysis of Sp-2 antigen in the presence of SDS revealed four constituents of 43, 35, 28 and 14 kDa. All these components reached with both IgM and IgG when tested by immunoblotting.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000032:analysis*; D000953:Antigens, Protozoan / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis* / Q000276:immunology; D007841:Latex Fixation Tests; D051379:Mice; D011817:Rabbits; D014122:Toxoplasma / Q000276:immunology*
chemical_list: D000906:Antibodies; D000953:Antigens, Protozoan; D007106:Immune Sera; D007074:Immunoglobulin G; D007075:Immunoglobulin M