Polymerase Chain Reaction

 The Polymerase Chain Reaction is used for amplifying specific DNA sequences. It was invented in 1984 by Kary Mullis. It is a quick an easy way to copy specific sections of DNA. The first step is known as 'Strand Seperation. This is where you take the sequence of DNA you want to copy and heat it to 95^oC. This causes the two strands of DNA to seperate as the Hyrdrogen Bonds between the bases break. The strands are heated for roughly 15 seconds. The next stage is reffered to as 'Hybridization of Primers' this is where primers are added to the DNA as it is cooled to 54^oC to allow the hydrogen bonds to form between the primers and the DNA strands. The primers both bind the the 3' end of the template and complementary strands. The Primers are typically 20-30 nucleotides long. The third stages is called 'DNA Synthesis'. The solution containg the DNA and primers is heated to 72^oC and the enzyme TAQ polymerase is added. This specific enzyme is found at bacteria that live in hot springs, therefore it is able to function at this high temperature. The TAQ polymerase lengthens the DNA in the 5'-to-3' direction and takes place on both strands .