title: An improved assay for radiation-induced chromatid breaks using a colcemid block and calyculin-induced PCC combination.
abstract: We report on a new method for the study of radiation-induced chromatid breaks in stimulated human peripheral blood T lymphocytes, involving a combination of a 1-h colcemid block and a short (15 min) calyculin A treatment. We find that this procedure eliminates the problem of centromere splitting when calyculin A is used alone for a longer period and produces metaphase spreads with superior quality. By this procedure, the chromosomes and the chromatid breaks are expanded and thereby make for improved break scoring. In a comparison of the new technique with the conventional colcemid block method, we show a close proportionality between the frequencies of chromatid breaks scored with the two methods. The frequency of chromatid breaks with the new method was found to be significantly higher than that with colcemid alone, adding a higher sensitivity to the assay as an additional advantage.
authors.affiliation: Bute Medical School, University of St Andrews, St Andrews, KY19 9TS, UK.
authors.forename: Olga
authors.initials: O
authors.lastname: Shovman
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Riches
authors.forename: Douglas
authors.initials: D
authors.lastname: Adamson
authors.forename: Peter E
authors.initials: PE
authors.lastname: Bryant
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D001943:Breast Neoplasms / Q000473:pathology; D002273:Carcinogens / Q000633:toxicity; D002478:Cells, Cultured; D002842:Chromatids / Q000235:genetics / Q000528:radiation effects; D042002:Chromatin Assembly and Disassembly / Q000187:drug effects*; D019457:Chromosome Breakage / Q000528:radiation effects*; D002877:Chromosomes, Human; D003703:Demecolcine / Q000494:pharmacology*; D006801:Humans; D008387:Marine Toxins; D009152:Mutagenicity Tests / Q000379:methods*; D010080:Oxazoles / Q000633:toxicity*; D011832:Radiation Injuries / Q000175:diagnosis* / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D002273:Carcinogens; D008387:Marine Toxins; D010080:Oxazoles; C059041:calyculin A; D003703:Demecolcine