Liver mtDNA content increases during development: a comparison of methods and the importance of age- and tissue-specific controls for the diagnosis of mtDNA depletion. by Morten, K, Ashley, N, Wijburg, F, Hadzic, N, Parr, J, Jayawant, S, Adams, S, Bindoff, L, Bakker, H, Mieli-Vergani, G, Zeviani, M, Poulton, J