Table of ContentsWhat is PCR?ProcedureImportance of PCRWhat is PCR?Polymerase chain reaction or PCR is the in vitro technique of DNA synthesis or we can say that it is a procedure of in vitro DNA replication. This technique is generally used in molecular biology for the amplification of a single copy or a few copies of a DNA segment. Once this procedure is completed, it leads to the generation of thousands or millions of copies of that particular DNA segment from the very rare DNA copies. This PCR technique is elegantly simple. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay: Components required in PCR: DNA template containing the target region. Two DNA primers. The synthetic oligonucleotides (the primers are prepared) must be complementary to the sequences on the opposite strands of the target DNA at the positions defining the ends of the segment to be replicated. These primers essentially serve as replication primers. A DNA polymerase enzyme. The primers are extended by this enzyme and polymerize the new DNA strand. In PCR, since high temperature is required, thermophilic DNA polymerases are used for polymerization of new DNA strands. Such as Taq DNA polymerase, Deep vent R DNA polymerase. Deoxynucleoside triphosphates or dNTPs (dATP, dGTP, dCTP and dTTP). A buffer solution to maintain the appropriate chemical environment. This is necessary for optimal enzymatic activity of the polymerase and its stability.Mg2+, a divalent cation.ProcedureThermal cycling is involved in this polymerase chain reaction. This thermal cycle consists of repeated cycles of heating and cooling of the DNA fusion and enzymatic replication reaction. It triggers a chain reaction in which exponential amplification of the DNA template takes place. The isolated DNA which contains the segment to be replicated is first heated briefly to denature it. After heating it, it is then cooled in the presence of the large excess of synthetic oligonucleotide primers. After that, 4 dNTPs along with Taq DNA polymerase are added to it and the primed DNA segment is selectively replicated in vitro. The heating, cooling, and replication cycle is repeated 25 to 30 times over the course of a few hours in an automated process. The three basic steps of PCR are: Denaturation (94-98°C); Annealing (50-65°C) and extension (72°C). This entire process can be described through the diagram below.Keep in mind: This is just a sample.Get a custom paper from our expert writers now.Get a custom essayImportance of PCRThis powerful technique is used in the case of (i) a medical diagnosis; (ii) forensic medicine and (iii) studies of molecular evolution. Valuable diagnostic information can be provided by PCR in medicine. Bacteria and viruses can be easily detected through the use of specific primers. For example, certain cancers are detected early using the promising PCR method. Mutations in certain growth control genes (ras genes) can also be identified by PCR. genetic testing, tissue typing, oncogene identification, etc. In addition to all this, PCR is used as an indispensable tool in forensic science, especially in DNA fingerprinting, genetic mapping, genetic testing, tissue typing, etc...