Use of Antigen-Antibody Reactions in Agar to Follow the Progress of Fractionation of Antigenic Mixtures: Application to Purification of Staphylococcal Enterotoxin

Summary Antigen-antibody reactions in agar, modified from the technic of Oudin, have been used to determine the minimum number and to some extent relative concentrations of antigens in enterotoxic solutions at various stages of purification. A simple technic has been devised for direct identification of antigens responsible for bands appearing in different tubes. Resolution of superimposed bands has been accomplished by diluting the antigen mixture. An example of quantitative data which can be used to determine relative concentrations of antigens in fractions of a mixture is presented. Some aspects of practical application in the fractionation of mixtures of antigenic materials are discussed. Staphylococcal enterotoxin has not as yet been identified with a precipitating antigen demonstrable by these methods.