Measurement of radiation-induced DNA double-strand breaks by pulsed-field gel electrophoresis.
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.
Ager
D D
DD
Radiation Oncology Research Laboratory, University of California, San Francisco 94143.
Dewey
W C
WC
Gardiner
K
K
Harvey
W
W
Johnson
R T
RT
Waldren
C A
CA
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
D004247:DNA