Polymerase Chain Reaction Essay
The technique of PCR: Polymerase Chain Reaction was introduced by an American scientist Kary Mullis, for which in the year 1993, he was jointly awarded the Nobel prize in chemistry, with Michael smith, for his contribution in site-mutagenesis. Kary was working as a chemist at the Cetus Corporation, a biotechnology firm in Emeryville, California, where he came across an idea to amplify a desired DNA strand generating thousands to millions of copies of an interested DNA sequence (Mullis, 1998). The enhancement made by Kary Mullis enable PCR to become a principal technique in biochemistry and molecular biology (Rabinow et al, 1996).
The technique comprises series of events (chain reaction) involving the activity of …show more content…
Generally, the hydrogen bond needs high temperature to denature and so the solution in the PCR tube is heated at 94 to 96C. It is crucial to retain this high temperature for prolonged period to make sure that the DNA strands have separated entirely.
After the molecules are denatured as per the first step and both strands are separated completely, the mixture is allowed to cooled down to the temperature as low as 50 to 60C. There are higher chances that both the strands of DNA molecule can join again at this temperature, so to avoid this the primers that are made up of short DNA molecule anneal to the DNA molecule at specific positions (Figure 2c). The two denatured strands of DNA are complementary to each other and thus move in opposite direction, as a result there are two primers – a forward primer (downstream) and a reverse primer