title: Radioimmunoassay for type A toxin of Clostridium botulinum.
abstract: A preparation of pure type A toxin of Clostridium botulinum was labeled with (131)I in the presence of chloramine-T and carrier-free isotope. The radioactive toxin ((131)I Tox) was used in a radioimmunoassay procedure similar to that of Berson and Yalow. Dilutions of antibody to the toxin, capable of binding 50% of the added (131)I Tox, were mixed with a sample of the labeled toxin and various concentrations of unlabeled toxin ('Cold' Tox). When concentration of Cold Tox were plotted against the ratio (131)I bound/(131)I not bound, a standard curve was established that could be used to estimate the concentration of Cold Tox in a test mixture. This assay was sensitive to as little as 100 mouse minimum lethal dose and was highly specific for the serological type of the toxin used.
mesh_terms: D000818:Animals; D001905:Botulinum Toxins / Q000032:analysis*; D002700:Chloramines; D002848:Chromatography, DEAE-Cellulose; D003014:Clostridium botulinum / Q000276:immunology*; D005069:Evaluation Studies as Topic; D007106:Immune Sera; D005779:Immunodiffusion; D007456:Iodine Isotopes; D008722:Methods; D011193:Potassium Iodide; D011817:Rabbits / Q000276:immunology; D011863:Radioimmunoassay; D012703:Serotyping
chemical_list: D002700:Chloramines; D007106:Immune Sera; D007456:Iodine Isotopes; D011193:Potassium Iodide; D001905:Botulinum Toxins