title: DNA chain growth as a function of age in intact and permeabilized WI-38 and MRC-5 cells.
abstract: The rate of incorporation of deoxythymidine triphosphate (dTTP) into acid-precipitable material of permeabilized MRC-5 and WI-38 cells as well as the rate of DNA chain growth in both intact and permeabilized cells was examined as a function of cell age. Although both the total rate of dTTP incorporation and the percentage of labeled cells decreased as cultures aged, we could detect no decrease in the rate of DNA chain growth from passages 29 to 53 for MRC-5 and from passages 34 to 50 for WI-38 cells. Since the older passages were in phase III growth and since, in our hands, the WI-38 cells used for this study senesced at passage 51, we conclude that a decrease in the rate of DNA chain growth is not related to in vitro aging.
mesh_terms: D002453:Cell Cycle; D002455:Cell Division; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism*; D004261:DNA Replication; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D013942:Thymine Nucleotides / Q000378:metabolism; D013997:Time Factors
chemical_list: D013942:Thymine Nucleotides; D004247:DNA; C024157:thymidine 5'-triphosphate