PCR! What can we do without you?!

The Polymerase Chain Reaction or PCR for short is a process which amplifies the gene of interest in vitro. This process was not possible in earlier times as there was no known enzyme that could survive the high temperature that is required in PCR, however it all changed when two scientists named Thomas D. Brock and Hudson Freeze discovered the enzyme Taq Polymerase in an achaea which they named Thermus Aquaticus. It was able to withstand high temperatures without denaturing as it is found thermal habitats around the world and more information regarding thermus aquaticus can be found here (http://www.absoluteastronomy.com/topics/Thermus_aquaticus). There are three steps involved in PCR which is exponential amplification, leveling off stage and plateau. The product is doubled for every cycle during the exponential amplification stage and only minimum amount of DNA (gene of interest) is required. During the leveling off stage, the reaction slows down and DNA polymerase (taq polymerase) will decrease in activity. Lastly, the reaction finally stops at the plateau stage due to lack of reagents. This technique has a number of uses which include DNA fingerprinting, gene cloning and recovery of ancient DNA (http://en.wikipedia.org/wiki/Polymerase_chain_reaction#PCR_in_diagnosis_of_diseases) has more information regarding the uses of PCR.