title: Measurement of radiation-induced DNA double-strand breaks by pulsed-field gel electrophoresis.
abstract: We have examined the use of pulsed-field gel electrophoresis (PFGE) to measure DNA double-strand breaks induced in CHO cells by ionizing radiation. The PFGE assay provides a simple method for the measurement of DNA double-strand breaks for doses as low as 3-4 Gy ionizing radiation, and appears applicable for the measurement of damage produced by any agent producing double-strand breaks. The conditions of transverse alternating field electrophoresis determined both the sensitivity of the assay and the ability to resolve DNA fragments with different sizes. For example, with 0.8% agarose and a 1-min pulse time at 250 V for 18 h of electrophoresis, 0.39% of the DNA per gray migrated into the gel, and only molecules less than 1500 kb could be resolved. With 0.56% agarose and a 60-min pulse time at 40 V for 6 days of electrophoresis, 0.55-0.90% of the DNA per gray migrated into the gel, and molecules between 1500 and 7000 kb could be resolved.
authors.affiliation: Radiation Oncology Research Laboratory, University of California, San Francisco 94143.
authors.forename: D D
authors.initials: DD
authors.lastname: Ager
authors.forename: W C
authors.initials: WC
authors.lastname: Dewey
authors.forename: K
authors.initials: K
authors.lastname: Gardiner
authors.forename: W
authors.initials: W
authors.lastname: Harvey
authors.forename: R T
authors.initials: RT
authors.lastname: Johnson
authors.forename: C A
authors.initials: CA
authors.lastname: Waldren
mesh_terms: D000818:Animals; D002478:Cells, Cultured / Q000528:radiation effects; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D004587:Electrophoresis, Agar Gel / Q000379:methods; D066298:In Vitro Techniques
chemical_list: D004247:DNA