title: Calibration of the comet assay for the measurement of DNA damage in mammalian cells.
abstract: We used X-rays from a linear accelerator and from a low energy therapeutic source to calibrate the single cell gel electrophoresis (comet assay), a widely used method to measure DNA damage. Gamma-rays from 60Co, with known efficiency in inducing DNA breakage, were used as reference. Human lymphocytes and one murine tumour cell line, F10-M3 cells, were irradiated under different experimental conditions. A similar relationship between radiation dose and induced DNA damage was obtained with gamma- and X-rays. A calibration curve was constructed to convert the comet assay raw data into break frequency. The median levels of DNA breaks and oxidative damage in circulating lymphocytes from healthy volunteers were calculated to be 0.76 and 0.80 breaks/10(9) Da, respectively, (0.50 and 0.52 breaks/10(6) bp). The values of oxidative DNA damage were in the same order of magnitude as those found by others with HPLC methods.
authors.affiliation: Department of Preclinical and Clinical Pharmacology, University of Florence, Florence, Italy.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Pitozzi
authors.forename: Stefania
authors.initials: S
authors.lastname: Pallotta
authors.forename: Manuela
authors.initials: M
authors.lastname: Balzi
authors.forename: Marta
authors.initials: M
authors.lastname: Bucciolini
authors.forename: Aldo
authors.initials: A
authors.lastname: Becciolini
authors.forename: Piero
authors.initials: P
authors.lastname: Dolara
authors.forename: Lisa
authors.initials: L
authors.lastname: Giovannelli
mesh_terms: D000328:Adult; D000818:Animals; D002138:Calibration; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D003037:Cobalt Radioisotopes / Q000737:chemistry; D020552:Comet Assay / Q000379:methods* / Q000592:standards*; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D051379:Mice; D008875:Middle Aged
chemical_list: D003037:Cobalt Radioisotopes