Polymerase Chain Reaction (PCR)


The polymerase chain reaction is a technique that allows DNA molecules of interest (usually gene sequences) to be copied in a simple enzyme reaction producing a sufficient quantity of the copied DNA for detailed analysis or manipulation. The method is a basic tool in molecular biology with widespread applications in biological and medical research.

Keywords: DNA polymerase; Taq; primer; template; amplification

Figure 1.

Polymerase chain reaction involves repeated cycles of incubation at three temperatures. The reaction is initially heated to above 90°C. At this temperature, the double‐stranded DNA template is denatured and becomes single‐stranded. The temperature is next reduced to 45–65°C. At this temperature, the oligonucleotide primers bind to their target sequences on the single‐stranded template. The temperature is then raised to 72°C and the Taq DNA polymerase begins to synthesize a new DNA strand complementary to the template strand beginning at the primers. Further cycles of incubation result in the synthesis of increasing amounts of the target sequence.


Further Reading

Erlich HA (ed.) (1989) PCR Technology: Principles and Applications for DNA Amplification. New York, NY: Stockton Press.

Erlich HA and Arnheim N (1992) Genetic analysis using the polymerase chain reaction. Annual Review of Genetics 26: 479–506.

McPherson MP and Hames BD (eds.) (1995) PCR 2: A Practical Approach. Oxford, UK: IRL Press.

Nanda SK and Jain SK (1995) In vitro nucleic acid amplification systems. Current Science 66: 421–429.

Ohan NW and Heikkila JJ (1995) Reverse transcription polymerase chain reaction – an overview of the technique and its applications. Biotechnology Advances 11: 13–29.

Reischl U and Kochanowski B (1995) Quantitative PCR – a survey of the present technology. Molecular Biotechnology 3: 55–71.

Twyman RM (1998) Advanced Molecular Biology: A Concise Reference, pp. 279–285. Oxford, UK: Bios Scientific Publishers.

Winter PC, Hickey GI and Fletcher HL (2002) Instant Notes in Genetics, pp. 255–258. Oxford, UK: Bios Scientific Publishers.

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Winter, Paul C(Sep 2005) Polymerase Chain Reaction (PCR). In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0005339]