Hybrid formation between bacterial endotoxins.

When endotoxins extracted from enteric bacteria were mixed in the presence of sodium deoxycholate, and the bile salt was subsequently removed by dialysis or by extraction with ethanol, a new type of endotoxin was formed. The latter material was as biologically active as the original endotoxins and possessed a combination of antigenic determinants that were previously unique to each of the individual endotoxins in the mixture. This hybrid formation between endotoxins was detected by immunodiffusion and radioautography and by quantitative precipitation procedures.