Abstract
The extraction of polysaccharide antigen, group specific antigen of Streptococcus, was carried out by the modified method of Slade. The antigen was extracted with 5% TCA at 90°C from whole dried cells and then aceton was added to the extraction. The polysaccharide, insoluble in aceton, was obtained as the precipitate. The precipitate was suspended in phenol-water and the insoluble material was discarded. By the addition of ethylalcohol to the phenol-water layer polysaccharide was obtained as the precipitate. The material was soluble in water and composed with 77% rhamnose, 18% hexosamine and 1.1% protein.
As the sensitizing polysaccharide antigen O-stearoyl polysaccharide was used and the stearoyl polysaccharide contains 6% of the ester. The group specific antigenicity of the purified C-polysaccharide was demonstrated not only by the absorption test and gel diffusion technique but also by the stearoyl polysaccharide sensitized red cell hemagglutination.
