Open AccessInduction of chromosome damage by ultraviolet light and caffeine: Correlation of cytogenetic evaluation and flow karyotype
Author(s) -
Cremer C.,
Cremer T.,
Gray J. W.
Publication year - 1982
Publication title -
cytometry
Language(s) - English
Resource type - Journals
eISSN - 1097-0320
pISSN - 0196-4763
DOI - 10.1002/cyto.990020504
Subject(s) - metaphase , karyotype , chinese hamster , microbiology and biotechnology , chromosome , biology , flow cytometry , ultraviolet , ultraviolet light , chromomycin a3 , ultraviolet irradiation , mitosis , cell culture , irradiation , genetics , chemistry , materials science , optoelectronics , photochemistry , gene , physics , nuclear physics
Abstract Asynchrononously growing cells of a M3‐1 Chinese hamster line were ultraviolet (UV) irradiated (λ = 254 nm) with UV fluences up to 7.5 J/m 2 . After irradiation, cells were incubated with or without 2 m M caffeine for 20 hr, then mitotic cells were selected by mechanical shaking. Their chromosomes were isolated, stained with Hoechst 33258 and chromomycin A3, and measured flow cytometrically. While the fluorescence distributions of chromosomes (flow karyotypes) from cells treated with UV alone or with caffeine alone were very similar to those of untreated controls, the flow karyo‐types of UV + caffeine‐treated cells showed a debris continuum that increased with increasing UV fluence suggesting an increased number of chromosome fragments. Visual evaluation of metaphase plates revealed that the percentage of cells with chromosome damage also increased steadily with increasing UV fluence. A high degree of correlation was observed between the relative magnitude of the debris level from flow karyotypes and the percentage of cells with chromosome damage and with generalized chromosome shattering, respectively, as determined from metaphase spreads.