Botulinum Toxin (Type A); Including a Study of Shaking with Chloroform as a Step in the Isolation Procedure

The type A toxin of Clostridium botulinum has been isolated and crystallized. It has proved to be a heat-coagulable protein having the solubility properties of a globulin. A step-by-step description of the purification procedure has been reported elsewhere (Lamanna et al., 1946). It is the object of the present paper to review some of the data which support the validity of the method and to discuss the properties of the toxin at various stages of purity. Special attention is devoted to shaking with chloroform as a method for the isolation of a protein. Abrams et al. (1946) have also reported a method for the purification of this toxin. In 1928 Snipe and Sommer reported the concentration of the toxin from the medium by acid precipitation. Subsequently Sommer (1937) found that the toxin could be extracted from the precipitate of acid-treated whole culture by resuspension of the acid precipitate in 1 per cent (0.075 M) sodium acetate solu-tion at pH 6.5 and centrifugation at this pH value to remove the bacterialcells and other insoluble matter. Carrying the purification beyond these first two