Mitochondrial DNA was depleted following TFAM silencing and COX1 mRNA expression was quantified relative to reference gene B2M 72 h post transfection (A). Protein was extracted 72 h post transfection and analysed by western blotting, probing for COX1, SDH70, and β-Actin proteins. Protein bands were quantified by densitometry, and optical density readings used to calculate the ratio of COX1 (B) and SDH70 (C) mitochondrial proteins relative to β-Actin loading control. A representative blot is shown in (D). Data in (A) are normalised to Scrambled control cells. Both experiments repeated 3 times, with each experimental repeat performed in triplicate (A) or duplicate (B, C). Data presented are means ± SEM. * p<0.05, ** p<0.01, *** p<0.001. COX1, Cytochrome c Oxidase 1; SDH70, Succinate Dehydrogenase 70 kDa subunit.