polymerase chain reaction (pŏl`ĭmərās') (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is sometimes called DNA amplification.

The Process

In PCR, DNA (see nucleic acid nucleic acid, any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis.
..... Click the link for more information. ) is immersed in a solution containing the enzyme enzyme, biological catalyst. The term enzyme comes from zymosis, the Greek word for fermentation, a process accomplished by yeast cells and long known to the brewing industry, which occupied the attention of many 19th-century chemists.
..... Click the link for more information. DNA polymerase, unattached nucleotide bases (the subunits that DNA is composed of), and "primers," short sequences of nucleotides designed to bind with an end of the desired DNA segment. Two primers are used: one primer binds at one end of the desired segment on one of the two paired DNA strands, and the other primer binds at the other end but on the other strand. The solution is heated to break the bonds between the strands of the DNA. When the solution cools, the primers bind to the separated strands, and DNA polymerase quickly builds a new strand by joining the free nucleotide bases to the primers. When this process is repeated, a strand that was formed with one primer binds to the other primer, resulting in a new strand that is restricted solely to the desired segment. Thus the region of DNA between the primers is selectively replicated. Further repetitions of the process can produce billions of copies of a small piece of DNA in several hours.

Development and Applications

PCR was developed in 1985 by Kary B. Mullis, who was awarded the 1993 Nobel Prize in chemistry for his work. It is used in DNA fingerprinting DNA fingerprinting or DNA profiling, any of several similar techniques for analyzing and comparing DNA from separate sources, used especially in law enforcement to identify suspects from hair, blood, semen, or other biological materials found at
..... Click the link for more information. and in medical tests to identify diseases from the infectious agent's DNA. In forensic use, the test can be used to compare two samples of DNA, usually by looking at matches (or mismatches) of six inherited traits (e.g., hair curliness) from each of the samples. Each trait is controlled by a single gene, each gene having at least two forms, or alleles, resulting in 21 combinations of these alleles, some of them very rare. A nonmatch conclusively excludes a suspect. PCR also is used in taxonomic classification classification, in biology, the systematic categorization of organisms into a coherent scheme. The original purpose of biological classification, or systematics, was to organize the vast number of known plants and animals into categories that could be named,
..... Click the link for more information. to help show evolutionary relationships between organisms on the molecular level. It has the advantage of being able to be used even when only very small samples, such as tiny pieces of preserved tissue from extinct animals, are available.

polymerase chain reaction (PCR)

Laboratory technique used to make numerous copies of specific DNA segments quickly and accurately. These are needed for various experiments and procedures in molecular biology, forensic analysis (DNA fingerprinting), evolutionary biology (to amplify DNA fragments found in ancient specimens), and medicine (to diagnose genetic disease or detect low viral counts). Invented by Kary Mullis, PCR requires a DNA template (as little as one molecule) to copy, nucleotides to build the copies, and the enzyme DNA polymerase to catalyze the formation of bonds between the nucleotide monomers. Each three-step cycle (separating the two strands of the DNA double helix, marking the ends of the segment to be copied, and catalyzing the formation of bonds), which takes only minutes to complete, doubles the number of DNA strands present in the reaction medium. Repetition of this cycle many times results in an exponential increase in the amount of DNA.

polymerase chain reaction [pə¦lim·ə‚rās ′chān rē‚ak·shən]

(cell and molecular biology)

A technique for copying and amplifying the complementary strands of a target deoxyribonucleic acid molecule. Abbreviated PCR.

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No references found			For standard PCR reactions, they are available in natural tubes with domed caps, while for fluorescent applications, such as QPCR (quantitative PCR), Ultra Clear Caps (available in both white and natural tubes) provide an optically clear window into the reaction for enhanced detection of the fluorescent signal. EasyStrip Snap Tubes for improved PCR workflow by Pharma A 4-[micro]L aliquot of each PCR reaction was checked for the presence of a specific amplification product by agarose gel electrophoresis (2% agarose, tris acetate EDTA [TAE gel], 50 volts) and ethidium bromide staining. Identification of larval sea basses (Centropristis spp.) using ... by Vandersea, Mark W.; Litaker, R. Wayne; Marancik, Katrin E.; Hare, Jonathan A.; Walsh, Harvey J.; Lem / Fishery Bulletin The target for the Bordetella pertussis PCR reaction is also found in Bordetella holmesii. Pertussis PCR testing at the Vermont Department of Health Laboratory by Vermont Nurse Connection			Pchilka, Olena PCI PCI bus PCI card PCI Configuration Utility PCI DSS PCI Express PCI Mezzanine Card PCI slot PCI steering PCI-ISA Passive Backplane PCI-SIG PCI-X PCIset PCjr PCL PCLIPS PCM PCMCIA PCMIA PCMS PCN PCNB PCP PCR PCR reaction PCradio PCRAM PCS PCS/Geneva PCSA PCSB PCT PCTE PCTE+ PCU PCX Pd PD disc PDA PDA phone PDB PDC PDC Prolog PDD PDD-63 PDEL PDELAN PDES PDF PDF JobReady			PCPV PCPW PCPX PCPy PCPZ PCQ PCQA PCQC PCQHA PCQHRA PCQL PCQM PCQN PCQR2 PCQT PCQVP PCQVP-PCQVG PCR PCR PCR PCR PCR amplification PCR amplification PCR amplification PCR microarrays PCR microarrays PCR microarrays PCR oil PCR oil PCR oil PCR reaction PCR SSCP PCR-ARMS PCR-DGGE PCR-HERA PCR-IS PCR-ISH PCR-MPH PCR-PHFA PCR-RFLP PCR-SB PCR-SSCP PCR-SSO PCR-SSP PCR-STR PCR-TGGE PCR/DGGE PCr/Pi PCR/RFLP PCR/SB PCR/SSO PCR1 PCR2 PCRA PCRAA

polymerase chain reaction (redirected from PCR reaction)

The Process

Development and Applications

polymerase chain reaction (PCR)

polymerase chain reaction
(redirected from PCR reaction)