Detection of Alu sequences and mtDNA in comets using padlock probes.
Single cell gel electrophoresis, or the comet assay, is widely used to measure DNA damage and repair. However, the behaviour of the DNA under the conditions used for the comet assay is not fully understood. In developing a method for studying specific gene sequences within comets, using 'padlock probes' (circularizable oligonucleotide probes), we have first applied probes that hybridize to Alu repetitive elements and to mitochondrial DNA (mtDNA). During the sequence of stages in the comet assay, mtDNA progressively disperses into the surrounding agarose gel, showing no tendency to remain with nuclear DNA in the comets. In contrast, Alu probes remain associated with both tail and head DNA.
Shaposhnikov
Sergey
S
Institute of Basic Medical Sciences, University of Oslo, PB 1046 Blindern, 0316 Oslo, Norway.
Larsson
Chatarina
C
Henriksson
Sara
S
Collins
Andrew
A
Nilsson
Mats
M
D020087:Alu Elements; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D020552:Comet Assay / Q000379:methods*; D004247:DNA / Q000737:chemistry; D004249:DNA Damage; D053938:DNA Fragmentation; D004260:DNA Repair; D004272:DNA, Mitochondrial / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D009693:Nucleic Acid Hybridization
D004272:DNA, Mitochondrial; D004247:DNA; D006861:Hydrogen Peroxide