Title: DNA Amplification by the Polymerase Chain Reaction
Abstract: Occasionally, a technique is developed that changes the kinds of questions that can be answered in biology. Within a few short years, the polymerase chain reaction (PCR) became just such a powerful tool for solving a myriad of basic and applied problems. Modifications of the PCR continue to be developed and these permit additional applications. The PCR is a method for amplifying (copying) small amounts of DNA or RNA. It can be used to isolate specific DNA fragments, end label DNA, clone cDNA and genomic DNA, sequence DNA, mutate specific DNA sequences, alter promoters, quantitate the amount of RNA or DNA, and identify molecular markers for taxonomic or ecological studies. The PCR requires a DNA polymerase, dNTPs, template DNA, and primers. Information about sequences at each end of the DNA to be amplified is needed in order to synthesize appropriate primers for “standard” (allele-specific) PCR. When two specific primers are used, amplification of DNA theoretically is geometric, producing large quantities of DNA suitable for sequencing, cloning, or probing. PCR methods that use single primers, such as random amplified polymorphic DNA (RAPD)-PCR, also can result in DNA amplification. RAPD-PCR uses short, randomly chosen primers to amplify multiple DNA segments in the genome. The resulting banding patterns (similar to bar codes) provide information about genetic variation within the entire genome of insects. The power of the PCR to amplify DNA is dramatic; theoretically even a single molecule can be amplified, although efficiency usually is lower. This power creates formidable problems with contamination and requires careful organization of PCR experiments and the use of adequate controls. However, because the PCR is relatively easy, novices in molecular biology can use it to study molecular systematics, evolution, ecology, behavior, and development.
Publication Year: 2013
Publication Date: 2013-01-01
Language: en
Type: book-chapter
Indexed In: ['crossref']
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Cited By Count: 9
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