Mitochondrial DNA as a non-invasive biomarker: accurate quantification using real time quantitative PCR without co-amplification of pseudogenes and dilution bias

Biochem Biophys Res Commun. 2011 Aug 19;412(1):1-7. doi: 10.1016/j.bbrc.2011.06.067. Epub 2011 Jun 15.


Circulating mitochondrial DNA (MtDNA) is a potential non-invasive biomarker of cellular mitochondrial dysfunction, the latter known to be central to a wide range of human diseases. Changes in MtDNA are usually determined by quantification of MtDNA relative to nuclear DNA (Mt/N) using real time quantitative PCR. We propose that the methodology for measuring Mt/N needs to be improved and we have identified that current methods have at least one of the following three problems: (1) As much of the mitochondrial genome is duplicated in the nuclear genome, many commonly used MtDNA primers co-amplify homologous pseudogenes found in the nuclear genome; (2) use of regions from genes such as β-actin and 18S rRNA which are repetitive and/or highly variable for qPCR of the nuclear genome leads to errors; and (3) the size difference of mitochondrial and nuclear genomes cause a "dilution bias" when template DNA is diluted. We describe a PCR-based method using unique regions in the human mitochondrial genome not duplicated in the nuclear genome; unique single copy region in the nuclear genome and template treatment to remove dilution bias, to accurately quantify MtDNA from human samples.

MeSH terms

  • Cell Line
  • Cells / chemistry
  • DNA, Mitochondrial / analysis*
  • Genetic Markers
  • Genome, Human
  • Genome, Mitochondrial / genetics*
  • Humans
  • Polymerase Chain Reaction / methods*
  • Pseudogenes*


  • DNA, Mitochondrial
  • Genetic Markers