1 INTRODUCTION Most viruses are rather small, with typical diameters of 10–150 nm, and their morphological study in cells requires the resolution of electron microscopy (EM). Together with the characterization of shape, size, and contacts with cellular structures, labeling and localization of viral and cellular macromolecules are very important to comprehend how viruses use cell materials to build their own structures. This micro-review presents two labeling methods: Immunogold and METTEM.
