Preparation and properties of diphtheria toxoids in submerged culture. II. Purification, detoxification, antigenicity, and stability

Abstract

Cornyebacterium diphtheriae was grown in submerged culture using a new semisynthetic medium, and high-potency diphtheria toxins were produced. These toxins were purified before detoxification by formalin–lysine mixtures. The resultant toxoids possessed a high degree of purity (Lf/mg non-dialyzable nitrogen), gave good antigenic responses in animals, and showed no tendency to revert to toxin. Toxins which had been detoxified with formalin alone before purification, however, showed marked reversion when diluted and stored at 25 or 34 °C. When tested in guinea pigs the lysine-treated toxoids were shown to possess good immunizing capacity, and no significant decreases in the antigenic potencies were observed in samples stored for prolonged periods of time at elevated temperatures.