The physical chemical basis for preserving cell structure for electron microscopy at the molecular level and available preparatory methods.

A method to prepare tissues for electron microscopy based on the kinetic theory of physical chemistry makes it possible to study the structure of cells at the molecular level because extensive denaturation of proteins is avoided in contrast to using conventional preparatory methods. The highly ordered arrangement of mitochondrial enzymes revealed by applying this method is discussed. Low temperature embedding, freeze-substitution, freeze-drying combined with low temperature embedding and freeze-fracturing are evaluated with respect to conditions for protein denaturation.