Polymerase Chain Reaction

By: Amber, Aakshi, Noah


Polymerase chain reaction, or PCR is used to make multiple copies of a segment of DNA. PCR is very precise and can be used to amplify, or copy, a specific DNA from a mixture of DNA molecules.


1. A piece of DNA is heated. This separates the two strands.

2. At each end of the original piece of DNA, a short piece of DNA that complements a portion of the sequence is added.

3. DNA polymerase copies the region between the primers. These copies serve as templates to make more copies.


of applications including genotyping, cloning, mutation detection, sequencing, microarrays, forensics, and paternity testing.


PCR helps make multiple copies of DNA. It's used to study crossing over during meiosis. It can be used to increase a sample of DNA when there isn’t enough to analyze (for example a crime scene), as a method of identifying a gene or to test for disease.