development of a recombinant protein-based dot-blot hybridization assay for the detection of antibody to chicken infectious bronchitis virus

nucleocapsid (n) protein of infectious bronchitis virus (ibv), one of the viral structural proteins, inducesstrong antibody response in natural infection. in this study, a simple, recombinant n protein-based dot-blottest was developed to serologically examine chicken serum samples for the presence of ibv antibody.initially, 72 serum samples were tested for the presence of ibv antibody using a commercial enzyme linkedimmunosorbent assay (elisa) kit. forty six ibv positive serum samples (group a) produced strong signalsin the dot-blot assay. seven negative serum samples (group b) produced weak but specific signals using thedot-blot assay in conjunction with western blot analysis. the remaining 19 samples (group c) from ibvnegative specific pathogen free (spf) chickens did not produce visible signals using the dot-blot assay. inconclusion, the above results suggest that the dot-blot assay is a reliable, sensitive, and specific test forserological detection of ibv positive chickens.