The use of chicken IgY in a double antibody sandwich ELISA for detecting African horsesickness virus

An indirect sandwich ELISA that can detect as little as 8 ng of African hor sesickness virus (AHSV) was developed. Viral antigen was captured from susp ension using an immobilized monoclonal antibody specific for an epitope on VP7, a protein that is a major constituent of the virus core. Egg-yolk deri ved chicken IgY directed against AHSV (serotype 3) was used as the secondar y antibody. Since IgY and mouse IgG do not cross-react serologically, the s econdary antibody was not labelled, but was instead detected with enzyme-co upled sheep antibodies directed against avian immunoglobulins. The assay re cognized all nine AHSV serotypes, but not the Cascara isolate of equine enc ephalosis virus, a related orbivirus that also infects horses. In addition to being able to detect and quantify whale AHSV, the ELISA could show the p resence of VP7 produced by recombinant baculoviruses.