Abstract
The cells of Saccharomyces cerevisiae labelled with 3H-uridine was studied by electron microscopic autoradiography. The silver deposits are localized over the cytoplasm of the mother cell as well as the daughter cell. It seems reasonable to conclude that the silver deposits are due to 3H-uridine incorporated into ribonucleic acid during growth of the cells. According to this observation, RNA synthesis and storage do not occur within the vacuole in yeast Saccharomyces.
