The Polymerase Chain Reaction or PCR is a DNA amplification process that has had a tremendous impact on both basic research and clinical diagnosis. In 1993, Kary Mullis was awarded the Nobel Prize for its development.

The polymerase chain reaction, or PCR as it is commonly referred to, has had such a profound impact on science that it has changed the types of questions that can be asked. PCR is used daily by thousands of individuals: from researchers seeking to understand disease processes and mechanisms to forensic scientists trying to solve crimes.

What is PCR?

It all comes down to DNA. DNA is copied in a similar manner by most organisms. DNA copies are made every time cells divide. PCR mimics this process in the laboratory. The key enzyme required for this replication process is DNA polymerase. As its name suggests, this enzyme is involved in joining the nucleotide bases (adenine, cytosine, guanine and thymine) to form a DNA polymer. In order for the DNA polymerase to do its job, the two strands of the DNA double helix must first be separated. Each strand is then used as a template for copying by the polymerase.

The Yellowstone connection

How did a little known bacterium contribute to the development of DNA replication by PCR?
A key breakthrough in the development of the polymerase chain reaction came from an unlikely source—a bacterium (Thermus aquaticus) found in a hot spring in Yellowstone National Park.

PCR-online.org is a PCR resource meant to help the research scientist or science student. You will find PCR protocols, troubleshooting for technical problems, theory and links to PCR-related information.