Measuring Oxidative mtDNA Damage and Repair Using Quantitative PCR

The human mitochondrial genome was completely sequenced in 1981 by Anderson and co-workers (1) and consists of a closed circular supercoiled DNA molecule of 16,569 base pairs. Mammalian cells characteristically contain a few hundred to several thousand mitochondria, each with 2-10 copies of the genome. The mitochondrial genome encodes 13 polypeptides, 22 transfer RNAs (tRNAs), and 2 rRNA. The 13 polypeptides encoded by the mitochondrial DNA (mtDNA) are essential subunits of the electron transport chain (ETC) and ATP synthase; cells lacking mtDNA are completely dependent on glycolysis for survival (2).