Polymerase chain reaction, or PCR, refers to a method of heat cycling to amplify DNA. It was made possible by the discovery of a thermophilic (heat loving) bacterium: thermus aquaticus. The DNA polymerase from this bacterium made DNA replication at high temperatures (60-70 degrees Celsius) possible.
PCR works by the cycling of several temperatures:
After an initial denaturing period, these three periods are cycled anywhere between 10 and 30 times, using various lengths for each period depending on what the researcher is working with. Most PCR machines will, after reaching the end of the cycling and completing the final elongation phase, hold the DNA at a very low (comparatively) temperature of 2-4 degrees Celsius for an infinite time, or until the researcher removes the DNA from the machine.
PCR was first developed in 1983 by Kary Mullis.[1]
Categories: [Chemical Reactions]