A fixation method for visualization of yeast ultrastructure in the electron microscope.

A primary fixative containing glutaraldehyde (3%), acrolein (1.5%), and paraformaldehyde (1.5%) buffered in 0.05 M sodium cacodylate at pH 7.2 was applied to the cells Cryptococcus vishniacii for 2 hours on ice. The cells were then treated with a 6% aqueous solution of potassium permanganate for 1 hour at room temperature. This method preserves most of the yeast cell fine structural components including cell walls and membrane, nuclear membrane, mitochondria, endoplasmic reticula, microbodies, vacuoles, nucleoli, and ribosomes. However, it leads to disruption of capsular materials and loss of some of the lipid and glycogen granules.