Figure A1.

Quantitation of mitochodrial DNA damage: DNA was prepared from CHO cells exposed to Na₂S (H₂S) or H₂O₂. qPCR of samples compared with that of a known amount of target sequence allowed absolute quantitation. This quantitative measurement was made either directly with CHO DNA preparation or after eight cycles of a long PCR amplifying a 8Kb fragment of mitochondrial DNA (2976–11031) including the qPCR target sequence (6744–6918). Therefore, after the long PCR the theoretical amplification factor of the mtDNA target sequence is 64 times. The graph represents the experimental amplification factor (Y axis) when cells were exposed to increasing concentrations (X axis) of H₂S (empty symbols) or H₂O₂ (filled symbols). The number of experiments (independent treatment with H₂O₂ or H₂S) is indicated. A log scale is used for both axes with following modifications: H₂S values are represented with X values 10% higher than reality, this allows distinction of error bars, the 10⁶ value (1M) Na₂S is represented as if 10⁴.