[Production of antiserum to neurotoxin-2 from Naja naja oxiana cobra venom and reaction with the toxin].

Antiserum to neurotoxin-2 from the venom of the cobra was obtained by immunization of rabbits via the injection of the toxin into the lymphatic nodes and by two re-immunizations via the injection of the toxin into the blood and intramuscularly. Using scores of micrograms of the toxin, specific antisera with high antibody titer were obtained. In spite of high specificity of separate stages of the reactions, using indirect immune fluorescence technique, no specific fluorescence was found in the end-plates of the diaphragm, in which "intact" cholinoreceptors were bound to neurotoxin-2. It is suggested that antigenic determinant of the toxin is involved into the formation of a firm link with the receptors, this process resulting in "masking" the determinant and in loss of its ability to react with antibodies.