Effects of dimethylsulfoxide on the ultrastructure of fixed cells.

It has been reported that the use of dimethylsulfoxide (DMSO) as a solvent for fixatives enhances preservation of cellular ultrastructure. By contrast, we have shown that DMSO alters the ultrastructural integrity of glutaraldehyde fixed cells. The cell membrane, nuclear envelope, endoplasmic reticulum, ribosomes, microtubules and intracytoplasmic organelles are most susceptible to the action of DMSO. We hypothesize that DMSO exerts intracellular alterations via its interaction with remnant interfacial water in fixed cells. DMSO-induced alterations of these and related cellular components may result in the formation of artefactual structures and networks. Thus, it appears that DMSO containing glutaraldehyde neither accelerates fixation nor enhances stabilization of cellular ultrastructure. For these reasons, addition of DMSO to fixatives is not recommended.