Studies on the O Antigen of <i>Salmonella Typhosa</i>

Abstract

Summary A method has been described for the further purification of the somatic antigen of S. typhosa. By this procedure, it was possible to isolate a phosphorylated lipopolysaccharide essentially devoid of the protein component initially present. This purified antigen, in its specific precipitative activity, stimulation of antibody production, and pyrogenic activity, equalled or exceeded preparations containing 5 to 20% protein. Chemical analyses of the purified O antigen showed that its principal components are polysaccharide, 60 to 70%; lipid 20 to 30%; and hexosamine, 3.5 to 4.5%.