A cytochemical study of the localization of acid phosphatase in Saccharomyces cerevisiae at different growth phases.

The localization of acid phosphatase in the yeast Saccharomyces cerevisiae at different growth phases had been studied. It was shown to be crucial for authentic location of acid phosphatase that the cytochemical reaction be performed on whole cells. Dimethylsulphoxide was used to alleviate the effects of fixation of the yeast cells with glutaraldehyde; the sulphoxide did not affect the distribution of acid phosphatase in the cells. It has been established that in exponentially-growing cells acid phosphatase is localized mostly in small vacuolar compartments. In mature cells, the bulk of acid phosphatase is found in the central vacuole, although a significant amount of the enzyme is detectable in the plasma membrane and the adjacent vesicles.