Hybridization by deoxycholate treatment or by biological degradation of bacterial endotoxins extracted from smooth and rough strains.

An endotoxin extracted with phenol-water from a rough microorganism (Salmonella typhi strain R(2)) was hybridized with an endotoxin obtained by the Boivin technique from a smooth strain (S. enteritidis Danysz) when they were mixed in the presence of sodium deoxycholate. These two toxic antigens could also be hybridized by incubation in citrated serum. With this new composite molecule, the presence of the hydrophilic side chains on the smooth moiety influenced the electrophoretic migration of the R antigen and greatly hindered the reactivity of the R sites with their specific antibodies.