What is the purpose of a PCR machine?

A PCR machine also known as a thermal cycler is a machine used to amplify segments of dna via the PCR which stands for polymerase chain reaction. PCR machines may also be used to test temperature sensitive reactions. The first step of the machine is to heat the samples to 94-96 degrees, then the temperature is lowered to 50-65 degrees, then the mixtures temperature is raised to 72 degrees to synthesize a new dna strand.