Reproducible Quantitative PCR of Mitochondrial and Nuclear DNA Copy Number Using the LightCycler

of target molecules. Before the invention of fluorimetric quantitative PCR, researchers who wanted to quantify the amount of a gene in a sample did so painstakingly by limiting dilution, competitive polymerase chain reaction (PCR), or other methods, including high-performance liquid chromatography (HPLC), solid phase assays, dot blots, or immunoassay (1 ).