title: Non-linear dose-effect curve for DNA double-strand breaks by low LET radiation: the effect of eluting buffer composition on the measurement of breaks by the filter elution technique.
abstract: Chinese hamster V79 cells were irradiated with 250 kVp X-rays and analysed for the presence of DNA double-strand breaks using filter elution. Changing the pH of the elution and lysis buffers from pH 9.6 to 7.2 leads to a decreased rate of elution of the DNA from the filters and a small difference in the dose-effect relationship obtained. In both cases the dose-effect curves were non-linear. When cells are irradiated with 238Pu alpha-particles a difference in the rate of elution of the DNA is also observed between the two pH values, although the dose-effect curves are linear. These findings suggest that there may be qualitative differences in the types of lesions being induced by low-LET radiation and being scored as dsb in the filter elution assay at pH 9.6. However, carrying out elution at pH 7.2 does not eliminate the nonlinear response measured after X-irradiation.
authors.affiliation: Cancer Research Campaign, Gray Laboratory, Mount Vernon Hospital, Northwood, Middlesex, UK.
authors.forename: K M
authors.initials: KM
authors.lastname: Prise
authors.forename: S
authors.initials: S
authors.lastname: Davies
authors.forename: B D
authors.initials: BD
authors.lastname: Michael
mesh_terms: D000512:Alpha Particles; D000818:Animals; D006224:Cricetinae; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D004735:Energy Transfer; D005374:Filtration / Q000379:methods; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques
chemical_list: D004247:DNA