How does the protein-based MT-BG1 assay stack-up against a PCR-based mtDNA assay?
A1. MT-BG1 provides more relevant information when considering the effects of a compound on mitochondrial biogenesis. Identifying and characterizing altered mitochondrial biogenesis requires consideration of the loss (or gain) of copies of mtDNA, translation and transcription rates of the encoded genes, and stability and assembly of the 13 mitochondrially-encoded subunits into the 5 OXPHOS complexes. Measuring protein levels as done with MT-BG1 summates all of these effects, and is equally informative of compounds that alter mtDNA replication, mitochondrial protein synthesis, or both. The figure above illustrates the loss of mtDNA, as measured by PCR, and the loss of mitochondrially-encoded protein (cytochrome c oxidase), as measured by MT-BG1, in the presence of 4µM ddC in cultured fibroblasts. Not surprisingly the reduction in levels of protein trails the loss of mtDNA as the protein complexes, including cytochrome c oxidase, have a significant half-life before degradation, but the c
