Factors Influencing the Speed of Flocculation

[摘要] 1. 1. The higher the Lf-units of diphtheria-toxin or anatoxin, the smaller the Kf-value, as has been asserted by many observers.2. 2. If diphtheria toxin or anatoxin is freed from accompanying substances by dialysis or purification by the calcium-phosphate method, its Kf-value becomes smaller.3. 3. The Kf-value of diphtheria-toxin or anatoxin largely depends on its pH. Irrespective of the kind of culture media in which toxin was produced, it was found that ( a ) the Kf of the purified and its original toxin is least in the untreated solution and increases with the amount of acid or alkali added. ( b ) When purified toxin was mixed with buffer solutions of different pH, the Kf was found to be the smallest in the mixture with the buffer of pH 6. ( c ) Both original and purified anatoxin had the smallest Kf-value in the most acid range within which flocculation did occur.4. 4. Anatoxin prepared from semi-synthetic broth toxin the Kf of which was found ∞, showed flocculation when it was dialysed, acidified or purified.

[学科分类] 生物科学（综合）