Polymerase chain reaction (PCR) is a laboratory technique used to amplify small amounts of DNA. It is a powerful tool that has revolutionized molecular biology and has a wide range of applications, including DNA sequencing, genetic engineering, and diagnosing genetic diseases.
PCR is based on the ability of the enzyme DNA polymerase to synthesize new DNA strands using a template DNA strand as a guide. The process involves three main steps: denaturation, annealing, and extension.
In the first step, denaturation, the double-stranded DNA template is heated to a high temperature, causing the two strands to separate, or denature.
In the second step, annealing, specific oligonucleotide primers, which are short DNA sequences complementary to the template DNA, are added to the reaction mixture. The primers bind to their complementary sequences on the template DNA strands.
In the third step, extension, the enzyme DNA polymerase synthesizes new DNA strands using the template DNA strands as a guide. The process is repeated multiple times, resulting in the exponential amplification of the DNA template.
PCR is a very sensitive technique, and small amounts of DNA can be amplified to produce millions of copies in just a few hours. This makes it an ideal tool for analyzing DNA from a variety of sources, including ancient samples, forensic samples, and clinical samples.
There are many applications of PCR, including DNA sequencing, gene cloning, and genetic engineering. PCR is also used in the diagnosis of genetic diseases, such as sickle cell anemia and cystic fibrosis, and in the detection of pathogens, such as bacteria and viruses.
For example, PCR can be used to amplify a specific gene or region of DNA for sequencing, allowing scientists to study the function and regulation of that gene. PCR can also be used to amplify a specific gene for cloning, allowing researchers to produce multiple copies of that gene for further study.
In genetic engineering, PCR is used to create genetically modified organisms by inserting a specific gene into the genome of an organism. PCR is also used in the production of genetically modified crops, which have been modified to be resistant to pests or to produce nutrients that are beneficial to humans.
Who invented PCR?
Polymerase chain reaction (PCR) is a laboratory technique used to amplify small amounts of DNA. It was invented by the American biochemist Kary Mullis in the early 1980s while he was working at Cetus Corporation, a biotech company based in Emeryville, California.
Mullis was awarded the Nobel Prize in Chemistry in 1993 for his invention of PCR, which he described in a patent application filed in December 1983. Mullis’s invention has had a major impact on the field of molecular biology and has led to numerous scientific and medical advances.
PCR is based on the ability of the enzyme DNA polymerase to synthesize new DNA strands using a template DNA strand as a guide. The process involves three main steps: denaturation, annealing, and extension. PCR is a very sensitive technique and can amplify small amounts of DNA to produce millions of copies in just a few hours. It is widely used in molecular biology and has a wide range of applications, including DNA sequencing, gene cloning, and genetic engineering.
In addition to his work on PCR, Mullis also made significant contributions to the field of nucleic acid chemistry. He was known for his innovative and unorthodox approach to science and was known for his independent and creative thinking. Mullis passed away in 2019 at the age of 74. His invention of PCR continues to have a major impact on the field of molecular biology and has led to numerous scientific and medical advances.
