Cytophotometric determination of unscheduled DNA synthesis

Kallol K. Bose, David C. Allison

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


We describe a cytophotometric assay for unscheduled DNA synthesis (UDS) in asynchronously growing cells. Monolayer cultures of human HEp–2 and mouse MCa–11 cells were incubated with the carcinogen methylmethane sulfonate (MMS), as well as with hydroxyurea and (3H)thymidine. Slides were prepared, and the DNA contents and areas of nuclei were measured by absorption cytophotometry. The labeling of the nuclei, determined on the basis of their DNA content to be in G0/G1, was selectively measured after the preparation of autoradiographs. The labeling of the G0/G1 cells increased with increasing doses of MMS. We also found that the increased nuclear labeling after MMS treatment was not due to induction of replicative DNA synthesis or selective destruction of G0/G1 cells. The results of this assay compared favorably with a standard biochemical method for measuring unscheduled DNA synthesis by benzoylated naphthoylated DEAE cellulose chromatography.

Original languageEnglish (US)
Pages (from-to)203-209
Number of pages7
Issue number2
StatePublished - Mar 1987
Externally publishedYes


  • DNA repair
  • autoradiography
  • carcinogen induced DNA damage

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Biophysics
  • Hematology
  • Endocrinology
  • Cell Biology


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