Procedure by which tiny amounts of a DNA sequences can be amplified in a chain reaction
PCR is the most commonly used way of detecting the presence of tiny traces of DNA sequences. Applications include:
To perform PCR, two short DNA sequences (primers) are needed that match up with the DNA sequences the researcher is trying to identify. If the target sequence is present, the primers initiate a chain reaction. Each cycle of the chain reaction duplicates the target sequence. After 20 to 30 cycles, millions of copies of the target sequence are present, making identifying the sequence relatively easy.