Circular dichroism and ethidium bromide binding studies of chromatin from WI-38 fibroblasts stimulated to proliferate.
Confluent monolayers of WI-38 diploid fibroblasts can be stimulated to proliferate by fresh serum. In the first 3 h after stimulation (that is, several hours before DNA replication) the chromatin of stimulated cells show structrual changes which include: (1) an increase in maximum positive ellipticity and a blue shift in the 250-300 nm region of circular dichroism spectra; and (2) an increase,in isolated chromatin, of the number of binding sites for the intercalating dye, ethidium bromide.The differences between chromtin  of stimulated and chromatin of unstimulated cells are abolised when bother chromatins are treated with 0.25 M NaCL.
D001665:Binding Sites; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002843:Chromatin / Q000187:drug effects / Q000378:metabolism; D002942:Circular Dichroism; D004261:DNA Replication; D004171:Diploidy; D004996:Ethidium; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D008168:Lung / Q000196:embryology; D009690:Nucleic Acid Conformation; D012965:Sodium Chloride / Q000494:pharmacology; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet; D013698:Templates, Genetic; D013997:Time Factors
D002843:Chromatin; D012965:Sodium Chloride; D004996:Ethidium