Ribonucleic Acid Synthesis in Synchronously Dividing Populations of HeLa Cells

Abstract

A NUMBER of investigations directed towards the description of the events occurring during the reproductive cycle of the mammalian cells have been made in randomly dividing cell populations. For example, the time-course of synthesis of DNA has been elucidated in several systems by use of microspectrophotometric or autoradiographic techniques^1–3. However, for investigations in which it is difficult to identify the stage of a cell in the mitotic cycle, synchronously dividing populations are of value. Recently, we were able to obtain large populations of mitotically synchronized HeLa S-3 cells by preferential detachment of cells in mitosis from nearly confluent monolayers growing in very low calcium medium. We report here some of our observations on the rate of RNA synthesis in synchronized HeLa cells during one division cycle.