Study on Diphtheria Toxin Purification: A New Approach to Prepare Toxoid

Two produce a high potency diphtheria toxin two methods of detoxilïcation were applied. In the revised method the toxin was purified before detoxification by formaldehyde-stabilizing agent mixture. In the convention al method the crude toxin \Vas detoxified by formaldehyde alone. In this method culture lïItrates contain numerous impuritics and metabolites that may cause heterogenous product. The potency and reversibility of toxoid prepared by the revised method were tested and showed desirable immunizing and irreversibility. It possessed a high degree of purity, potency, recovery and showed no tendency to revert to toxin. Our results indicate that the purilïcation index and recovery percentagc in the revised method was significantly improved (p<O.O 1) as compared with the conventional method. The percentage of purification 25, rccovery 15.6, and potency 9.8 were increased in the revised method.