Problems of the use of 2,2-dimethoxypropane as dehydrating agent in preparing single cells for transmission electron microscopy.

Dehydration with 2,2-dimethoxypropane acidified with 1 n HCl in an 1:100 volume ratio has been found to be unsuitable for the preservation of cell membranes in single cell preparations. Reducing the HCl concentration to 0.1 or 0.01 n results in an improvement of membrane structures. This effect is rather independent of different fixation modes, buffer concentrations, or embedding media. It is suggested that membrane destruction is caused by a proton concentration exceeding a suitable level.