polymerase chain reaction abbr., PCR (rus. полимеразная цепная реакция abbr., ПЦР) — polymerase chain reaction is an experimental method of molecular biology, which yields a significant increase in the number of specific DNA fragments.

Description

PCR method is based on the multicycle copying (amplification) of a specific region of target DNA. Such copying is carried out by the enzyme thermostable DNA polymerase in the presence of deoxyribonucleoside triphosphates (dNTPs) and synthetic oligonucleotide (20 - 25 nucleotide pairs) primers for DNA synthesis. The primers are complementary to the flanking regions of the target sequence located on opposite DNA strands. After primer annealing on opposite DNA strands, their 3'-ends are directed towards each other. Since the synthesis of new complementary DNA strands is initiated by the 3'-hydroxyl group of the primer, the DNA region flanked by the primers is amplified. Repetition of PCR cycles leads to an exponential increase in the copy number of the target DNA fragment according to the 2n formula, where n is the number of amplification cycles. There are multiple types of PCR techniques (Reverse Transcription PCR, Asymmetric PCR, Nested PCR, Inverse PCR, Touchdown PCR, etc.) designed for special tasks, as well as quantitative PCR variants including the widely used real-time PCR (Quantitative Real Time PCR). The real-time PCR is based on the detection of fluorescence of amplification products by introducing fluorescent components (fluorescently labeled probes or primers, or fluorescent dyes that intercalate into double-strand DNA) into the reaction mixture. In nanobiotechnology , the PCR is widely used to produce large amounts of specific DNA sequences for different applications (to fabricate probes, vectors, chips, DNA molecules of defined geometric shape, etc.).

Illustrations

Polymerase chain reaction process [2].

Polymerase chain reaction process [2].


Authors

  • Naroditsky Boris S.
  • Borisenko Grigory G.
  • Nesterenko Lyudmila N.

Sources

  1. Glick B., Pasternak J. Molecular Biotechnology: Principles and Applications of Recombinant DNA. — 3rd ed. Sigma Publishing, 2003, 784 pp.
  2. Analysis of the genome. Methods (in Russian). / Edited by K. Davis. — Moscow.: Mir, 1990. — 246 P.

Contact us