Andrew Ren6/1/00Chem 30HProf. FooteThe Automation of the Polymerase Chain ReactionWhen undergoing research on different organisms, researchers often rely onreplicating the organism s DNA in order to track down it s correspondent genes and/orthe proteins they are associated with. In the process, one copy of DNA is needed to bereplicated many times in order to achieve maximum efficiency in their study.The method of repeatedly replicating a segment of DNA is to use the polymerasechain reaction, or PCR, which was invented by Kary B. Mullis in the mid 1980s, then atCetus Corporation. PCR involves an enzyme known as DNA polymerase, which at thattime was extracted from microbes. The DNA polymerase can produce a large amount ofthe needed DNA by repeatedly copying the desired segment. Unfortunately, this processrequires the mixture to be alternately cycled between high and low temperatures. DNApolymerase works perfectly fine during the low temperature portion, but when exposed tohigher temperature, it stopped working. Therefore, technicians at that time had tocontinually refill the supply of DNA polymerase.A solution was found when the Cetus corporation isolated the DNA polymerasefrom the microbe T. aquaticus, a thermophile capable of living and thriving above 70degrees Celsius. Because this DNA polymerase, also known as Taq polymerase, tolerateshigh temperatures, its use in PCR technology has allowed the process to become fullyautomated. Recently, the DNA polymerase from the thermophile Pyrococcus furiosus(Pfu polymerase) was found to work best at an even higher temperature of 100 degreesCelsius. However, Pfu polymerase costs three to four times as much as Taq polymerasebecause of its high heat tolerance.Polymerase chain reaction is most commonly used in DNA fingerprinting, such asthe O.J. Simpson trial, biological research, medical diagnosis, and screening forsusceptibility of various diseases.Copyright 1999 Access Excellence @ the National Health Museum.http://www.accessexcellence.org/AB/GG/polymerase.htmlReferences1. Michael T. Madigan and Barry L. Marrs , Scientific American Online, FeaturedArticles: April 1997: Extremophiles