Polymerase Chain Reaction (PCR)

Since it’s first introduction in the year 1983, Polymerase Chain Reaction (PCR) has very rapidly become a fundamental tool for improving the health and human life. PCR was developed by Dr. Kary Mullis, who was at the time working for Cetus Corporation as a chemist. PCR is the quick and efficient method for making unlimited copies of each and every inch of DNA. It can also be adapted to allow amplification of RNA samples as well as DNA samples from any type of organism. PCR is simplified into a 3-step process, which is repeated for 30-40 cycles.

The procedure begins with the first step called denaturation. In the phase of denaturation, the structure of the DNA is altered. The double-stranded DNA melts and exposes into two pieces of single-stranded DNA at approximately 94 degrees Celsius. Transitioning into the second step called annealing or in other words, pairing up together. At a temperature of 54 degrees Celsius, the primers cool down and join to the single-stranded DNA or “template”. The double-stranded DNA then attaches to the polymerase and starts to shoot out copies.

Finally during the last stage of the PCR process known as elongation or extension, the polymerase works it’s magic. At 72 degrees Celsius the DNA building blocks are paired up with the DNA primers, to create a double-stranded DNA molecule. After all the processes are completed in one cycle round, a single portion of double-stranded DNA is finally enlarged into two separate pieces of double-stranded DNA. However, as the cycles repeat themselves, more and more clones are generated and the number of DNA copies are intensified exponentially. The procedure of doing a PCR is more vital than we may fathom.

It has been found to cure and diagnose genetic diseases, locate bacteria and viruses, DNA fingerprinting, study paternity, biological relationships, and human evolution. All in all, PCR has become widely known to biologists, DNA labs, and many other forensics laboratories. PCR is also one of the quickest testing methods to many diseases, for example The Human Immunodeficiency Virus, commonly known as HIV. HIV is a very difficult disease to find and eradicate. The earlier tests depended on the presence of antibodies in the human bloodstream.

When performing the antibody test, there may be no results until weeks after exposure to the virus. Nevertheless, when performing a PCR test results appear much faster, and as little as one genome among 50,000 host cells can be easily detected. PCR can efficiently detect the forensics of HIV, rather than the antibodies contained in the blood. The same goes for Tuberculosis, which are also complicated in sampling from patients, PCR tests speed up the results so that precautions may be taken as soon as possible. PCR testing is one of the many ways that can assist in detecting several diseases, and yet PCR is very vital to the human life.