Abstract
Immunogold technique in electron microscopy proved to be effective to demonstrate the virusantibody specificity using purified reference strains of infectious pancreatic necrosis virus (IPNV). Although some cross reactions were detected, it was possible to distinguish the major IPNV serotypes (Sp, Ab and WB) according to the different affinity for the antisera against the three reference strains which were binded to protein A-gold particles. Moreover, tubular structures with a diameter of 60 nm were detected presenting a high affinity for the gold particles, which suggests a viral origin.
