A low dose of ethidium bromide leads to an increase of total mitochondrial DNA while higher concentrations induce the mtDNA 4997 deletion in a human neuronal cell line

N. von Wurmb-Schwark, L. Cavelier, Gino A Cortopassi

Research output: Contribution to journalArticle

14 Scopus citations


Ethidium bromide (EtBr) is widely used to deplete mitochondrial DNA (mtDNA) and produce mitochondrial DNA-less cell lines. However, it frequently fails to deplete mtDNA in mouse cells. In this study we show by using a highly sensitive real-time PCR, that low doses of EtBr (10 μM) did lead to a three-fold increase of the total amount of mitochondrial DNA in a human neuronal cell line (Ntera 2). A higher dose of EtBr (25 μM) led to the expected decrease of mtDNA until day 22 when the cells almost died. Cell growth and mtDNA content could be restored after additional 22 days of non-EtBr treatment. The highest concentration of 50 μM also led to a significant increase of mtDNA. The cells died when they had only about 10% of mtDNA left, indicating a mtDNA threshold for cell survival. Additionally, the so-called common 4977 bp deletion could be induced by prolonged exposure to ethidium bromide. Whereas the higher doses led to significant higher amounts of deleted mtDNA.

Original languageEnglish (US)
Pages (from-to)57-63
Number of pages7
JournalMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
Issue number1-2 SPEC. ISS.
StatePublished - Apr 11 2006



  • 4977 bp deletion
  • Ethidium bromide
  • MtDNA
  • Ntera 2 cells
  • Real-time PCR

ASJC Scopus subject areas

  • Health, Toxicology and Mutagenesis
  • Molecular Biology

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