PCR

PCR is the acronym for "Polymerase Chain Reaction". It is an enzymatic amplification technique (Taq polymerase) which allows a large number (several million) identical copies of a fragment DNA to be obtained from a single fragment. The reaction is carried out in vitro. It is very valuable for fossil DNA studies as only very small amounts of genetic material are available.

PCR DNA fragment gene amplification machine (Credit: Magnus Manske).