Describe the requirements, process and applications for Polymerase Chain Reaction (PCR)

Requirements·            Original DNA sample (to be amplified)·            dNTPS (4 DNA nucleotide bases)·            Thermal cycler (reaction vessel)·            Buffer solution (to maintain stable pH)·            Taq Polymerase·            DNA primers (forward and reverse) Polymerase chain reaction (PCR) is a method used to amplify DNA. It uses repeated cycles of heating and cooling to make many copies from one original DNA sample. The process has three steps: denaturing, annealing and extension. In denaturing, the cycler is heated to 95 degrees which causes the DNA strands to unwind and separate. It is then cooled to 55 degrees, which allows the complementary forward and reverse primers to attach to the DNA. This is the annealing phase. The cycler is then heated again in the third phase, allowing Taq Polymerase (heat resistant DNA Polymerase) to add nucleotides to the 3’ end of the DNA strand. This leads to the formation of a newly synthesised DNA strand.