Studies on the Antigenicity of Bacterial Polysaccharides Part 4: On the B. Proteus XK Polysaccharide

By using trichloracetate method, diethylene glycol method, and trypsin method, the author has extracted (or digested) polysaccharide from B. Proteus XK. Then after comparing the respective quantity and purity of the polysaccharide derived by each method, the following results have been obtained. 1) Polysaccharide has been extraced (or digested) from B. Proteus XK with the aid of trichloracetate, diethylene glycol, or trypsin. On account of the refining process-that is, the filtering by the Seitz-Werke filter, this polysaccharide is reduced to 1/6-1/47. When dried, it is further reduced to 1/4-1/25. 2) Trichloracetate method yeilds more quantity in purer form than the other two methods. 3) It is possible to preserve this polysaccharide for a long period of time.