The possible use of native foot-and-mouth disease nonstructural protein 3A in a serological screening test

ELISA's for antibodies to non-structural proteins of foot-and-mouth disease developed to date use recombinant proteins as antigens. To compare the antibody response to recombinant antigen and native antigen we developed an antigen capture ELISA for foot-and-mouth protein 3A. The concentration of 3A protein in virus cultures was significantly higher in the cell debris than in the supernatant, which made it possible to use proteins directly eluted from cells separated from a virus culture using Filteraid. The antigen was trapped between one monoclonal antibody coated to the plate, and a second monoclonal antibody conjugated with horseradish peroxidase. The reaction of the second (conjugated) monoclonal antibody could be blocked by several post-infection sera. Further research has to be performed to determine whether or not this method can result in a reproducible serological test.