title: [Diphtheria toxin titration using "Staphylococcus aureus" protein A (author's transl)].
abstract: The antigen-antibody reaction between diphtheria toxin and its corresponding IgG antibody may be visualized if IgG are adsorbed on the surface of S. aureus cells carrying protein A (SpA). If enough antigen is mixed with SpA--IgG, a visible agglutination occurs. On a glass slide, a rapid test can detect 0.3 Lf/ml toxin. If the mixtures are incubated overnight at 37 degrees C, the highest dilution of toxin producing agglutination is 0.01 to 0.02 Lf/ml for a given batch of toxin. The sensitivities of this or of the biological titration using the lethal effect on guinea-pigs are the same. The high sensitivity of the skin reaction was however not approached.
mesh_terms: D000372:Agglutination Tests / Q000379:methods*; D000818:Animals; D000937:Antigen-Antibody Reactions; D004167:Diphtheria Toxin; D006168:Guinea Pigs; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A; D013211:Staphylococcus aureus
chemical_list: D004167:Diphtheria Toxin; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A
vernacular_title: Titrage de la toxine diphtérique utilisant la protéine A de Staphylococcus aureus.