Changes

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.

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.<ref>Bartlett & Stirling (2003)—A Short History of the Polymerase Chain Reaction. In: Methods Mol Biol. 226:3-6</ref>

PCR was first developed in 1983 by [[Kary Mullis]].<ref>Bartlett & Stirling (2003)—A Short History of the Polymerase Chain Reaction. In: Methods Mol Biol. 226:3-6</ref>

==References==

==References==