Development of indigenous ELISA for rotavirus diagnosis & its comparison with commercial kit

Preparation of reagents for the diagnosis of rotavirus by enzyme linked immunosorbent assay (ELISA) was carried out at the National Institute of Virology (NIV), Pune. This is a double antibody sandwich ELISA test. The coating antibody was raised in guinea pig against SA-11 (Simian rotavirus), and is used at 1:20,000 dilution. The indicator antibody was also raised against SA-11 in rabbits. The rabbit preimmune serum is used as negative control serum. Both, pre- and post-immune rabbit antisera are used at 1:10,000 dilution in the test. Goat IgG-HRP conjugate against rabbit IgG was procured commercially (Sigma, USA). Results of ELISA test can be read visually. A total of 63 pretested faecal specimens and 38 specimens of rotavirus in different concentrations were compared simultaneously by the NIV ELISA and Dakopatts ELISA. Of the 63 specimens, 36 were positive in NIV ELISA and 33 positive by Dakopatts ELISA. Human and animal rotavirus strains also showed higher titers in NIV ELISA than Dakopatts ELISA. From our data we conclude that NIV ELISA is 100 per cent specific and more sensitive than Dakopatts ELISA test. It is much more economical than any other commercial kit available for the diagnosis of rotavirus. Since the reagents are in lyophilized form, they are suitable for use in developing countries.