The matrix 1 (M1) gene, present in all subtypes of avian influenza virus (AIV), was cloned and expressed in Escherichia coli. Reactivity of the expressed protein was confirmed by western blot. Subsequently, the M1 gene expression product was purified and used as the antigen to develop a latex agglutination test (LAT) for detecting antibodies against these conventional subtypes of AIV including AIV H3, H5, H7, and H9 from chicken sera. The LAT is specific for AIV, and no cross-reaction was shown with chicken antisera against other avian viruses. Compared with the hemagglutination inhibition tes...
