Virus electron microscopy

Abstract

Since the introduction of the first electron microscope in 1939, the development of the field of ultra-structure, in both the physical and biological sciences, has been dramatic in its elucidation of problems in both fields. Although the theoretical limit of the resolving power of the instrument 2^oA was achieved early in its development, further refinements followed rapidly. Modern instruments are capable of reaching high vacuum levels in relatively short time periods and computerisation has made these instruments remarkably user friendly. The development of oil diffusion pump technology led to the ability to attain extremely high vacuum levels, an essential feature in allowing a beam of electrons to travel in a focused stream, through the use of condenser, objective and projector lenses striking a fluorescent screen, thus producing an image of the specimen to be examined.