[A study of pancrealysates of Sh. flexneri 2a and Sh. sonnei fractionated by filtration through Sephadex G-200 and ultracentrifugation].

A high-molecular fraction of the O-antigen of Sh. flexneri and Sh. sonnei was isolated from the antigen complex by gel-filtration through Sephadex G-200 and ultracentrifugation. The high-molecular fraction obtained by ultracentrifugation at 105000 g contained no low-molecular components.