Estimation of Vibrio cholerae and Escherichia coli heat-labile enterotoxin by enzyme-linked immunosorbent assay (ELISA).

By Enzyme-Linked Immunosorbent Assay (ELISA) purified cholera and Escherichia coli enterotoxins can be detected as sensitively as by CHO cells. There is a linear relationship between toxin concentrations and extinction values. In plates sensitized with toxins, antitoxins can be titrated with high sensitivity. ELISA cross-titration experiments demonstrate the existing antigenic relationship between cholera toxin and heat labile E. coli enterotoxin. Plates sensitized with either anti-E, coli-IgG or anti-cholera-IgG are suitable for detecting both cholera toxin, and E. coli LT. ELISA seems to be a simple, sensitive and economic method for quantitation of enterotoxins and toxin-specific antibodies.