Chemical Investigations on the Active Principles of the Phenomenon of Local Skin Reactivity to Bacterial Filtrates Iii. Application of Dialysis to the Production of the Active Principles in Fluid Media*

I t is known that the yield of staphylococcus toxin in plain broth and other fluid media is poor (1). The use of solid or semisolid agar media appears necessary for producing active preparations. Recently, however, McClean (1) was able to obtain potent toxins by the use of fluid media diffused through cellophane bags. The surface of the cellophane membrane appeared to play a r61e similar to that of the agar. I t was our consistent observation (2) that "agar washings" contain the most potent substances necessary for eliciting the phenomenon of local skin reactivity to bacterial filtrates. I t was of interest, therefore, to investigate the production of these substances when various bacteria were grown in the diffused medium described by McClean. The possibility of applying this method successfully was suggested by the previous observation that the active principles of the phenomenon were retained by cellophane membranes (3). The present paper embodies experiments on (a) the production of the active principles from various microorganisms grown in the diffused broth medium; and (b) the purification attained when culture filtrates so obtained were redialyzed.