The invention provides monoclonal antibodies and related binding proteins that bind specifically to the envelope glycoprotein of H5 subtypes of avian influenza virus (“AIV”). The monoclonal antibodies and related binding proteins are useful for the detection of H5 subtypes of AIV, including the pathogenic H5N1 subtypes. Virus may be detected in formalin preserved, paraffin embedded specimens as well as frozen specimens and biological fluids. Accordingly, the invention provides for the diagnosis and surveillance of dangerous viral infections.
