Reversible binding of vibrio cholerae toxin on NAD-sepharose

When a crude or partially purified culture of Vibrio Cholerae is passed through a column of NAD-Sepharose, the skin toxic material is bound to the gel. Choleragen may be recovered by increasing the ionic strength of the elution buffer, as shown by the skin test, immunodiffusion against anti-choleragen antiserum and polyacrylamide gel electrophoresis. Affinity chromatography on NAD-Sepharose may be helpful for the concentration and purification of Choleragen.