This book presents a wide variety of immuno-gold techniques for use in virus diagnosis and research. Protocols are presented for state-of-the-art techniques, including in situ hybridization, freeze substitution, and the utilization of ultra-small probes and replicas for use by virologists and electron microscopists identifying and studying viruses, their components, and replication in cells. The procedures are described by eminent scientists and are pertinent to both experienced researchers and newcomers to this field who are interested in the localization of low antigenic mass structures.