Production of monoclonal antibody against the nucleocapsid (N) protein of infectious bronchitis virus (IBV)

Infectious bronchitis virus (IBV) is an important viral pathogen of chickens with several serotypes. Efficient control of the infections caused by IBV relay on the vaccination and rapid diagnosis of infections. The nucleocapsid (N) protein of the virus is a conserved structural protein, considered as a candidate antigen for developing diagnostic kits and production of monoclonal antibodies. In the present study the N protein of infectious bronchitis virus, H120 vaccine strainwas expressed in Escherichia coli in order to be used as antigen for the production of monoclonal antibodies. Two monoclonal antibodies (1F9 and 6C3) reactive against the recombinant N protein were produced and tested for their reaction with the native viral N protein by Western blotting and immunodot. Both antibodies recognized the N protein in Western blotting but only 1F9 antibody was positive in immunodot. 1F9 antibody also reacted with 4/91 and QX stains of IBV. It appears this monoclonal antibody possess the diagnostic application.