Antibody Response In Cattle Research Articles

Summary Very potent botulinum toxin Types C and D can be produced in intussuscepted cellophane tubing immersed in nutrient medium. This “dialysate” toxin is 50 to 100 times as potent as toxins prepared in the conventional way. The “dialysate” toxins contain 1/50th to 1/100th of the protein nitrogen per M.L.D., Lf, and L+dose contained in the best of the non-“dialysate” toxins. The M.L.D./mg protein nitrogen of type D “dialysate” toxin is approximately the same as that of pure Type A toxin. Formol-toxoids prepared from these “dialysate” toxins are up to 8000 times as efficient in eliciting immunity as conventionally prepared toxoids. A striking feature of these easily prepared toxoids is their low protein content. A dose that will provoke a very high antibody response in cattle may contain as little as 0.001 mg protein nitrogen. The method is very suitable for preparing botulinum formol-toxoids on a large scale. Much less labour and effort is required than is needed in the preparation of toxoids by conventional methods. There is evidence that the method can be adapted to the preparation of other Clostridial toxins.

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