Low voltage high-resolution SEM (LVHRSEM) for biological structural and molecular analysis

Abstract

High-resolution scanning electron microscopy (HRSEM) is being used increasingly to gain new insights into three-dimensional organization of biological structure, macromolecular complexes and interactions of cellular components as well as isolated cell organelles. Modern scanning electron microscopes (SEMs) combined with adequate sample preparation can now provide resolution comparable with that achieved using transmission electron microscopes (TEMs) down to 2-5 nm for biological material. The versatility of the instrument and new sample preparation techniques have allowed detailed analysis of chromosomes, cytoskeletal components, virus and other biological material that has not been possible with TEM. The present review addresses resolution and specific specimen preparations for HRSEM, and highlights the importance of specimen preparation and choice of methods to achieve optimal results for proteins, macromolecular complexes and subcellular structures using low voltage HRSEM (LVHRSEM).