Generation of protective immune sera by Crotalus durissus terrificus venom detoxified by controlled iodination.

1. Whole soluble venom from the snake Crotalus durissus terrificus was detoxified by controlled iodination. Doses equivalent to 100 LD50 of the native venom were administered to mice, without signs of intoxication. 2. The non-toxic iodinated derivatives were able to stimulate antibodies in rabbits and horses within a short period (6 months) of immunization. Horse antisera attained titers of 0.5 to 0.9 mg/ml for protection against native venom. 3. Horse antisera obtained in horses from native and iodinated venom were run against both native and iodinated venoms, as antigens, in gel immunodiffusion. The precipitation lines showed total identity of the two types of sera.