Low temperature scanning electron microscopy: advantages and applications.

Cryo-preparation of specimens for scanning electron microscopy can be completed within a few minutes. Chemical fixation and contact with solvents is avoided, levels of specimen hydration are maintained, low melting-point materials are stabilized, volume changes are minimized and internal structure can be revealed by freeze-fracture. Elements are not lost or substantially relocated prior to X-ray microanalysis and specimen luminescence is enhanced. The displacement of internal structure and material subject to X-ray microanalysis by the growth of ice crystals in hydrated samples can be minimized by adopting fast freezing methods designed to limit ice crystal growth. The technique enables a wide range of industrial and biological materials to be examined rapidly and free from artifacts commonly associated with more conventional preparation methods.