Cholera enterotoxin (CT) and heat-labile enterotoxin (LT) produced by enterotoxigenic Escherichia coli share a common antigenic determinant. In addition, CT and LT each have a unique antigenic determinant. Antisera were prepared by immunoaffinity chromatography against these unique antigenic determinants, that is, antiserum that reacted with CT but not with LT and antiserum that reacted with LT...