ABSTRACT
The transmission electron microscope extended the magnification to 250,000X and the resolution to 0.5 nm or better. It has allowed high magnification examination of the effects of trace element imbalances and/or factors that alter their metabolism within rodents and other mammals. The goal of specimen preparation for electron microscopy is to fix and preserve cellular and extracellular components with minimal alteration. Chemical fixatives, such as paraformaldehyde, glutaraldehyde, and osmium tetroxide, are utilized to cross-link and stabilize cellular molecules. Electron micrographs not only allow an investigator to qualitatively assess tissue samples, but also to quantitatively assess various aspects of cells. Quantitative comparison of cellular component dimensions of experimental-treatment rodents to controls can be used to assess the treatment impact. A number of the chemicals used in the preparation of tissue for electron microscopy are toxic and should be handled with care.
