What is PCR and Gel Electrophoresis?
• Polymerase chain reaction (PCR) is a technique which is used to amplify the number of copies of a specific region of DNA, in order to produce enough DNA to be adequately tested. This technique can be used to identify with a very high-probability, disease-causing viruses and/or bacteria, a deceased person, or a criminal suspect.
• Gel electrophoresis is a widely used technique for separating electrically charged molecules. It is a central technique in molecular biology and genetic laboratories, because it lets researchers separate and purify the nucleic acids DNA and RNA and proteins, so they can be studied individually. Gel electrophoresis is often followed by staining or blotting procedures used to identify the separated molecules.
What is it used for?
• PCR has very quickly become an essential tool for improving human health and human life. Medical research and clinical medicine are profiting from PCR mainly in two areas: detection of infectious disease organisms, and detection of variations and mutations in genes, especially human genes.
• In the world of forensics, gel electrophoresis is used to obtain a DNA fingerprint of a criminal. This means that scientists can accurately tell whether two pieces of DNA, one found at a crime scene and one belonging to a suspect, are matches.
Who invented it?
• Developed in 1983 by Kary Mullis, PCR is now a common and often indispensable technique used in medical and biological research labs for a variety of applications.
• Gel electrophoresis was invented by Fred Sanger in 1975, who received a Nobel Prize for this work.
The Basic Steps of PCR
There are three basic steps in a PCR, which are repeated for 30 or 40 cycles. This is done on an automated cycler, which can heat and cool the tubes with the reaction mixture in a very short time.
The basic PCR steps are:
1. DENATURATION (at 94 degrees C). During this step, the double strand melts open to single