PCR is an interesting technique for the study of DNA. It is used extensively in NHS hospitals genetic labs as a means of testing for genetic diseases, but also has many further uses.
PCR is a technique which cuts a specific section of DNA or RNA and then amplifies that section up to increase the concentration. This can be seen in the image below.
Each of the stages of PCR is temperature dependent. The denaturation stage occures approx 95 oC, the annealing stage at around 50-60 oC and the extending and elongation stage occurs between 70 and 80 oC. These stages are repeated a number of times to obtain the required level of amplification, however ~30 times is common.