Electron microscopic methods for virus diagnosis

Viruses are obligate parasites that act as infectious agents on living organisms and are able to replicate only within their hosts. These are biological nanoparticles that can be isualized only through microscopes. Electron microscopy (EM) is a basic diagnostic tool used to observe and characterize viruses because of their higher resolution limit. Hence, EM has numerous applications in plant, animal, and in clinical virology. Generally, EM consists of two classes as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEMs are used to characterize the surface topography of a given specimens where electron beams (EBs) interact with the surface of the material. In TEM, EB penetrate through the specimen and provide details related to the internal structures. Therefore, this chapter elaborates on the EM as a diagnostic tool in virology and its structure and functions. Also, how to prepare biological specimens for EMs is explained as well.