In 1983, Kary Mullis, PhD, a scientist at the Cetus Corp., conceived of polymerase chain reaction (PCR) as a method to copy DNA and synthesize large amounts of a specific target DNA. Mullis and Cetus scientists presented their data in 1985 at the American Society for Human Genetics annual meeting. Their results were reported in the first-ever publication of the process later that same year.

The technique has revolutionized many aspects of current research, including the diagnosis of genetic defects and the detection of the AIDS virus in human cells. The technique is also used by criminologists to link specific persons to samples of blood or hair via DNA comparison. PCR also affected evolutionary studies because large quantities of DNA can be manufactured from fossils containing but trace amounts.

The procedure requires placing a small amount of the DNA containing the desired gene into a test tube. A large batch of loose nucleotides, which link into exact copies of the original gene, is also added to the tube. A pair of synthesized short DNA segments, that match segments on each side of the desired gene, is added. These “primers” find the right portion of the DNA, and serve as starting points for DNA copying. When the enzyme Taq DNA Polymeras from the bacterium, Thermus aquaticus is added, the loose nucleotides lock into a DNA sequence dictated by the sequence of that target gene located between the two primers.

On January 15, 1989, Cetus announced an agreement to collaborate with Hoffman-LaRoche on the development and commercialization of in vitro human diagnostic products and services based on PCR technology. Roche Molecular Systems eventually bought the PCR patent and associated technology from Cetus for $300,000,000.

In 1993, Mullis was awarded the Nobel Prize in Chemistry ‘for his invention of the polymerase chain reaction (PCR) method.’