General PCR.

The primary purpose of polymerase chain reaction (PCR) is to rapidly make many copies of a specific region of DNA or RNA so that it can be adequately detected, often by agarose gel electrophoresis. PCR is routinely used to amplify, modify, and clone genes for expression studies. There are many other applications for PCR, including paternity testing, biological relationships, mouse genotyping, diagnosing genetic diseases, forensics, and finding bacteria and viruses.