Detection of DNA strand breaks induced by hydroxyl radicals in nuclear and chromosomal chromatin by electron microscopy.
Chinese hamster Don cells were treated with 10 mM hydrogen peroxide. DNA strand breaks induced by hydroxyl radicals were amplified in 3' termini by an exonuclease III digestion, resulting in single stranded DNA motifs. In situ detection of these motifs was performed on chromatin fibres of isolated whole-mounted nuclei and chromosomes by a random priming procedure, using biotinylated-dUTP which bound a gold-tagged streptavidin. This approach facilitated the location of hydroxyl radical induced DNA breaks, specifically on 20-30 nm diameter chromatin fibres, by transmission electron microscopy.
Laboratorio de Dosimetría Biológico, Centro Oncológico de Galicia, La Coruña, Spain.
J L
JL
Fernández
J
J
Gosálvez
V J
VJ
Goyanes
D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000648:ultrastructure; D002843:Chromatin / Q000648:ultrastructure*; D002875:Chromosomes / Q000648:ultrastructure; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000648:ultrastructure; D004249:DNA Damage; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008854:Microscopy, Electron
D002843:Chromatin; D004247:DNA; D006861:Hydrogen Peroxide