Purification and crystallization of Clostridium botulinum type C toxin.

A procedure for purification and crystallization of Clostridium botulinum type C toxin is described.The toxin was precipitated from the culture by addition of zinc chloride and eluted by dibasic sodium phosphate solution from the precipitate.The toxin was precipitated with ammonium sulfate to 34 % saturation at 4C and the toxin solution dissolved in acetatf'-phosphate buffer was chromatographed by the connected columns of Sephadex G-75-DEAE cellulose-QAE Sephadex A-50 at pH 7.0.The eluate had a specific toxicity of 3.8 X 10 7 MLDjl.O E277.5mwThe toxin was crystallized from the solution dialysed against the saturated ammonium sulfate solution by ultrafiltration.The crystalline toxin had a specific toxicity of 3.0 X 10 7 MLD/LO E277.5m!, and a faint hemagglutination activity.The crystalline toxin contained at least two components in acrylamide gel electrophoresis and the agar gel immunodiffusion test, respectively.