Improved ELISA for Russell's viper (Daboia russelii) antivenom potency

Abstract

An improved ELISA to assay Russell's viper (Daoboia russelii) antivenom potency was developed by selection of a suitable antigen fraction from the snake's complex venom. Venom was chromatographed on Sephadex G-100 and gave two major peaks (R1 and R2), with apparent molecular weights of 170,000 and 21,000, respectively. Using the viper crude venom, R1, and R2 as antigens, ELISAs were developed to quantitate the respective horse antibody in 15 batches of antivenom against the viper. The in vivo neutralizing activities of these of antivenoms were also determined in mice. Regression analysis of in vivo neutralizing activities versus ELISA titers of these antivenoms gave correlation coefficients r of 0.67 (p < 0.001), 0.82 (p < 0.001), and 0.13 (p < 0.05) for the crude viper venom, for R1 and for R2, respectively. Thus, for the in vitro assay, the high molecular weight venom protein fraction, R1, served as a better ELISA antigen than the crude venom. This ELISA should be useful for the improvement and standardization of antivenom potency.