Ultrastructural localization of viral antigens using the protein A-gold technique.

HSV and DNV viral antigens have been localized by electron microscopy using the protein A-gold technique. The labelling of HSV antigens was detected over the (naked and enveloped) viral particles as well as on the cytoplasm and the nucleoplasm. In contrast, DNV antigens were revealed only over clusters of viral particles in the nucleus. The high sensitivity of the technique and the good ultrastructural preservation allowed a very fine identification of the labelled structures. Thus, the protein A-gold technique can be applied generally for the ultrastructural detection and identification of viral antigens and might be useful for diagnostic purposes.