Question

What is PCR? Who discovered PCR technique?

Answer 1

This is a widely used technique nowadays, It's a technique for amplifying a piece of DNA or making a large number of copies. To put it another way, PCR allows you to make millions of copies of a certain DNA sequence from a little sample – often as little as a single copy. In many steps this process is completed.

Complete answer:
Kary B. Mullis pioneered the Polymerase Chain Reaction (PCR) technology in 1985, which enables scientists to make millions of copies of a rare DNA sample. Many elements of current research have been transformed by the technology, including the diagnosis of genetic abnormalities and the detection of the AIDS virus in human cells. Criminologists utilise the technology to match specific people to blood or hair samples via DNA comparison. Because vast amounts of DNA may be generated from fossils having only tiny amounts, PCR has had an impact on evolutionary studies.
A small amount of DNA carrying the target gene is placed in a test tube as part of the operation. A big batch of loose nucleotides is also fed to the tube, which join together to form precise duplicates of the original gene. A pair of manufactured short DNA segments are introduced that match portions on both sides of the intended gene. These are known as "primers" and they locate the correct segment of DNA and act as starting places for DNA replication. The free nucleotides lock into a DNA sequence determined by the sequence of the target gene placed between the two primers when the enzyme Thermus aquaticus (Taq) is introduced.
When the test tube is heated, the double helix of DNA splits into two strands. As the temperature is decreased, the primers automatically attach to their corresponding parts of the DNA sample, exposing the DNA sequence of each strand of the helix. At the same time, the enzyme binds the free nucleotides to the primer as well as each of the split DNA strands in the proper order. The entire reaction takes about five minutes and produces two double helices that include the desired fraction of the original. The heating and chilling process is repeated until the quantity of DNA copies is doubled. After thirty to forty cycles are completed a single copy of a piece of DNA can be multiplied to hundreds of millions.

Note:
Cetus and Hoffman-LaRoche established a collaboration on the development and commercialization of in vitro human diagnostic goods and services based on PCR technology on January 15, 1989. The PCR patent and associated technology were later purchased by Roche Molecular Systems for $300,000,000 from Cetus.