Flor

Polymerase Chain Reaction
The polymerase chain reaction (PCR) is a rapid and simple method for copying an specific part of the “information” that you has in the body (DNA).For use this method, it is necessary to know what it is the region that you want to copy.
The DNA is formed by two large chains; the Polymerase Chain Reaction is initiatedwhen the chains of the DNA are fused at high temperature and then the mixture is cooling. This mixture is incubated with DNA polymerase I (enzyme with which the cell makes theDNA) and with the links of the chains (A, C, T and G). This allowing the polymerase to synthesizing new DNA. The polymerase synthesizes DNA with the help of a piece of a chain,the primers. The original chain is used as a template to make the new chain, but with an opposite sense.
The PCR has two cycles. The first cycle ends when the chains withdifferent sense are created. The second cycle is initiating when the mixture of the chains is refunded. In the DNA synthetic step of the second cycle, each chain synthetized in thefirst cycle serves as an additional template having made it with the appropriate primers. The second cycle is completed when DNA polymerase I extend the primers to synthetizedthe complement.
PCR reactions can be conducted for 20 or more cycles. These reactions are routinely automated by using temperature controlled cyclers.
PCR has many uses. Forexample, is used for the cloning of known genes or genes related to know genes. It also can be used to detect, or in some cases to quantify, the presence of particular parts ofthe DNA (for example, the presence of viral parts in a clinical specimen).
Finally, PCR can amplify DNA only when the primers are near each other.

Student: Florencia Muñoz