Monoclonal antibodies raised against bluetongue virus detect viral antigen in infected tissues using an indirect immunoperoxidase method.

An indirect immunoperoxidase method was developed to determine the presence of viral antigen in bluetongue virus (BTV) infected tissues. Embryonating chicken eggs were infected with each of the 4 United States BTV serotypes (10, 11, 13, 17) and the chorioallantoic membranes were subsequently formalin fixed and embedded in paraffin. The infected membranes were examined for the expression of viral antigen. Monoclonal antibodies raised against BTV 17 (BT 21A and BT 98A) were used as the primary antisera in the immunoperoxidase procedure. Excellent specific staining was observed when each of the antisera was applied to membranes expressing antigens of homologous BTV serotype. BT 98A showed outstanding reactivity with membranes infected with heterologous BTV serotypes as well.