Evaluation of the Antigenicity of Tetanal Toxoid

Summary If the tetanal flocculative reaction is carried out in the described manner, flocculating toxins show the average ratio of Lf:L+ as 1:10. The MLD values of tetanal toxins do not parallel the antigenicity of the tetanal toxoids prepared therefrom. Combining power values (L+ or Lf) of tetanal toxins cannot always be used for evaluation of antigenicity of the corresponding toxoids. For certain toxins prepared under defined conditions, however, a parallelism exists. The most reliable method of determining the antigenicity of tetanal toxoid is by means of an antigenicity test carried out in guinea-pigs or in mice.2