Use of gold IgG complexes and human antisera for electron microscopic identification of hepatitis A virus and...

An indirect immunogold staining technique was used for identification of hepatitis A virus and poliovirus types 1,2 and 3 by electron microscopy. Human convalescent antisera against hepatitis A virus and the three poliovirus types were used as primary antibodies and goat anti-human IgG gold complexes, with an approximate gold granule size of 15 nm, as secondary antibody. Hepatitis A virus was specifically labelled with the homologous antiserum. No labelling was observed when antiserum against poliovirus or other negative control sera were used as primary antibody. Poliovirus types 1, 2 and 3 were specifically labelled with a human serum with high titres of antibody against all three virus types. The use of type-specific antisera made it possible to distinguish types 1, 2 and 3 from each other, although slight cross-reactions occurred. The results indicate that gold IgG complexes in conjunction with human antisera may be used for identification of small spherical viruses.