[Biological and immunological researches on snake venom. V. Application of the immunochemical technics to the titration of specific antibodies to the alpha toxin of Naja nigricollis venom (author's transl)].

In order to establish a simple method to titrate antitoxin antibodies in the antivenom sera, we suggest a new immunochemical technic. To a constant dose of a pure toxin extracted from a snake venom, increasing volumes of specific immune serum are added so as an excess of toxin remains free. This residual toxin is titrated by electroimmunodiffusion technic according to Laurell or by radial immunodiffusion method of Mancini. The experimental results in vitro are compared to those obtained in vivo. If a given volume of immune serum neutralize X microgram of toxin by the in vivo technic it will combine in vitro to 2 X or 1.2 X of the same toxin, respectively if we refer to electroimmunodiffusion or to radial immunodiffusion technic results.