Effectiveness of sodium bisulfite on the stability of Russell's viper (Daboia russelli siamensis) venom toxoid under various storage conditions

Crude Russell's viper venom toxoid was prepred by slow and step-wise formalinization to a final concentration of 0.8 per cent formalin. Then 35 per cent sodium bisulfite was added to half volume of the toxoid. Two types of toxoid were stored at different storage temperatures. At two monthoy interval, the immunogenicity of these toxoid were tested in mice. The antibody levels in immunized mice were measured by ELISA. The toxoid with sodium bisulfite was more immunogenic than the toxoid without it. Therefore the reversion of formaldehyde lindage during storage was less in toxoid which contained sodium bisulfite.