Development and Standardization of ELISA as Pre-screen Test for the Potency Estimation during Commercial Production of Antisnake Venom Serum (ASVS)

Abstract

In vivo neutralization assay is the only accepted method for the potency testing of antisnake venom serum (ASVS), till today. Due to non-availability of any other methods, this assay is considered as gold standard for potency testing. However, it requires large number of animals. There is an increasing need over the years to develop an in vitro alternate method so as to reduce/abolish the use of animals. Further, newer method may prove less complicated, sensitive, less expensive and less laborious for potency testing of antivenom. The present study was planned to develop, standardize an ELISA assay for the potency testing of ASVS and to validate its utility as a pre-screen test during commercial production. The ELISA assay was standardized and validated critically and, was applied to test the potency of purified anti Cobra venom serum and polyvalent ASVS. Different variables were tested to determine optimal antigen–antibody concentrations, antigen-coating conditions and the assay validation as per the WHO recommendations. The ELISA assay was found to be specific and sensitive with marked reproducibility. Further comparison of in vitro and in vivo result indicated that ELISA method can quantitate the anticobra Ig’s in the serum, accurately as high degree of correlation > 0.9 was obtained between both the assays. The result suggests that ELISA can be used as a pre-screen assay to the conventional in vivo assay during initial stages of antivenom production.