Cell-Free DNA

Mitochondrial cfDNA is assessed using target sequences from mitochondrial and nuclear genomes by real-time quantitative PCR on a ViiA 7 system, tested in duplicate. Plasma for cfDNA extraction is separated using two centrifugation steps to avoid post-collection lymphocyte lysis, which could artificially increase cfDNA. If cfDNA concentrations are at least 5 to 10 ng/mL, methylation capture screening may be used to infer tissue or cell origins.