A method for observing intracellular structures of free cells by scanning electron microscopy

A new method is described for scanning electron microscopic observation of cultured free cells using chitosan embedding. Intracellular structures of free cells can be clearly observed using a combination of the chitosan embedding and the Osmium-DMSO-Osmium (O-D-O) method. Chitosan, a polysaccharide, is not affected by the osmium maceration procedure central to the O-D-O method, which destroys other possible embedding media such as gelatin, agar, egg albumin and fibrin. Chitosan cracks to yield a fracture face which is featureless at low magnifications, and causes no recognizable artefacts.