Studies of the division cycle of human cancer cells (HELA) using a new system for continuous synchronization

Abstract

HeLa S3 cells have been induced to divide synchronously in suspension culture through more than ten generations. Cellular DNA and RNA have been determined at hourly intervals throughout the cell cycle defining the pattern of nucleic acid accumulation in HeLa cells. Cellular activity of the enzymes thymidine kinase, alkaline DNase, catalase, acid phosphatase and lactic dehydrogenase has been determined as a function of the division cycle. The method of synchronization developed here allows the continuous synchronous growth of mammalian cells in suspension culture. This system facilitates studies of cell cycle events since it provides a large amount of cellular material with minimal maintenance time required.