Use of prokaryotically expressed nucleocapsid protein as positive antigen in ELISA

A cDNA library of Rinderpest vaccine virus was prepared in Zap Express vector (Stratagene). The Rinderpest 'N' gene specific clones were selected, characterized and thereafter expressed in E. coli XLOLR strain. The expressed protein was found to be immunogenic in western blot with hyperimmune sera. It reacted with rinderpest and 'N' protein specific monoclonal antibodies in Enzyme Linked Immunosorbent Assay (ELISA). Prokaryotically expressed 'N' protein also gave precipitin band in counter immunoelectrophoresis test (CIE). The expression of N protein was sufficient for its utility as positive antigen in CIE and ELISA used for rinderpest diagnosis.