Production of Rabbit Antisera to the Staphylococcal Enterotoxins

An immunization method for production of antiserum to the staphylococcal enterotoxins in rabbits is presented. The bleeding schedule is tailored to the enterotoxin type. About 0.5 mg of staphylococcal enterotoxin is used per rabbit and serum harvest begins 11 weeks after the initial injection. Proposed are subcutaneous injections of 1, 3, 10, 20 and 30 μg of toxin with Freund's adjuvant on days 0, 3, 8, 24 and 28, respectively; and five weeks later, injections of 50, 100 and 300 μg on days 0, 3 and 8, respectively. Serum harvest ranges from a 4-week period for enterotoxin A to 8 or more weeks for enterotoxin E. Immunizations with all toxin types using the proposed or similar injection programs produced antibody titers from about 20 to over 100. Individual variation in response of rabbits in the same group was generally 3- to 5-fold, and in extreme instances, 10-fold. Immunization experiments were augmented by booster experiments in which the rabbit variable was held relatively constant by sequentially testing different schedules and doses on the same group of animals.