Accumulation of S Phase Populations of FM3A Cells Growing in the Mouse due to Administration of 5-Fluoro-2'-Deoxyuridine

Abstract
We have established procedures for the accumulation of an S phase population of FM3A cells grown in the mouse. Mice were kept for 5 days after intraperitoneal inoculation with 1 x 106 FM3A cells, then they were treated with 100 μg of 5-fluoro-2'-deoxyuridine for 16 h. When the FM3A cells were taken from the mice and cultured in vitro, more than 70% of the cells synthesized DNA, and the cell number increased 1.8-fold after 14 h. DEAE-cellulose column chromatography of the nuclear extract fraction showed that the synchronized cells contained about three times the activity for DNA polymerase a than that of random cells. Activity in the cytoplasmic fraction remained at the same level.