Polymerase Chain Reaction (PCR) is a molecular biology technique for enzymatically replicating DNA without using a living organism, such as E. coli or yeast. Like amplification using living organisms, the technique allows a small amount of the DNA molecule to be amplified exponential. However, because it is an in vitro technique, it can be performed without restrictions on the form of DNA and it can be extensively modified to perform a wide array of clever genetic manipulations. (wikipedia)

PCR is commonly used in medical and biological research labs for a variety of tasks, such as the detection of hereditary diseases, the identification of genetic fingerprints, the diagnosis of infectious diseases, the cloning of genes, paternity testing, and DNA computing. Whenever they do DNA work on TV (aka CSI) it uses this technique. Kary Mullis won the 1993 Nobel Prize in Chemistry for inventing PCR.

Laboratory, USA.

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