The Method of Diluting Antigen in Relation to the Wassermann Reaction

Abstract

Twenty-four years ago Sachs and Rondoni found that for the Wassermann test, alcoholic extracts of tissues diluted by adding salt solution slowly to the extracts with continuous shaking to secure turbid emulsions were more antigenic than when extracts and saline were rapidly mixed to produce opalescent or fairly clear emulsions. They also observed that turbid emulsions were slightly more anticomplementary than opalescent emulsions; that is, the former absorbed slightly more complement themselves than the latter. In other words these investigators observed that turbid emulsions of alcoholic tissue extracts for the Wassermann test were more antigenic than opalescent emulsions but since then this important factor relating to the manner or method of diluting antigen for the Wassermann test has not received the attention that it deserves. Browning and McKenzie confirmed these observations and also noted that turbid emulsions of alcoholic lecithin-cholesterin extracts of ox liver were more antigenic than opalescent emulsions but that there were practically no differences in their anticomplementary properties when the complement had been kept for eighteen to twenty-four hours before use. Noguchi in 1911 recommended the use of an opalescent emulsion of his extract of acetone-insoluble lipoids prepared by quickly mixing extract and salt solution as being most certain in action but in 1923 advised adding the salt solution drop by drop to the extract to secure the maximum of turbidity and antigenic activity. Kolmer advised the use of turbid emulsions secured by adding antigen slowly to saline solution and at this time Bronfenbrenner