Experiments with cholera toxin detoxified with glutaraldehyde

Studies on the production, purification, and detoxification of cholera toxin are reported. The toxin was first partially purified with aluminium hydroxide and further purification was effected with Bio Gel A-5m and Sephadex G-75. The toxins were detoxified with glutaraldehyde; the toxoids so obtained, when injected into the skin of rabbits, appeared to have no residual toxicity. All the toxins were immunogenic. The toxoid partially purified with aluminium hydroxide retained most of its immunizing capacity, but the highly purified toxoids did not retain their capacity to stimulate antibody production in rabbits.