PCR – based diagnostics, which will help to determine the main communicable and hereditary diseases

PCR – based diagnostics, which will help to determine the main communicable and hereditary diseases

PCR diagnostics will detect the main hereditary diseases

PCR or polymerase chain reaction is one of the newest and most accurate methods of determining the main hereditary diseases, which made a splash in the field of diagnosis and molecular biology.

This method makes it possible to convert genetic material into acceptable units necessary for further research. It is due to this method that it became possible to decipher the human genome and a new field of activity – biotechnology. Today, this rather cheap and effective method is used literally every day in many practical areas, far beyond academic science. For example, PCR helps to diagnose diseases and track treatment progress, identify bacteria and viruses, conduct paternity tests, study mummies and even look for criminals. Thus, PCR can be called one of the greatest discoveries of the 20th century.

How does PCR detect major hereditary diseases?

The method is based on the fact that each living organism has its own unique sequence of DNA and RNA genes (in the case of viruses). This allows to immediately determine if the body has a foreign microorganism. If there is even a ghostly trace of someone else’s DNA in the sample, it means that the body already has some infection. However, with such a diagnosis there is a slight problem: as a rule, laboratory technicians have only a small example of biomaterial – saliva, a drop of blood, hair. This is not enough to perform a full examination. This issue was able to solve the biochemist from America Cary Mullis – his approach allowed to repeatedly increase the smallest DNA sample, so that the material was suitable for high-quality diagnosis. 10 years after its discovery, Mullis received the Nobel prize in chemistry.

Everyone knows that DNA consists of two spiral threads – it is in them that all genetic information about the body is located. Mullis disconnected the coils, and then placed one label on each end. He then used DNA polymerase molecule to create a copy of DNA segment between the marks. So he doubled the amount of material. If perform this action again and again, it is possible to get a huge number of identical spirals. As a result of each PCR cycle, the element of the necessary DNA is doubled, and the cycle can be repeated any number of times. Modern equipment allows to multiply DNA elements to thousands of pairs in just a few hours.

It is noteworthy that before the discovery of this method, the cloning of a DNA fragment by conventional methods took from six to two years, required many units of expensive equipment and specialists of a very high level. Now everything becomes much easier: just a couple of hours and a small part of the genetic material. Since DNA is perfectly preserved, PCR method can be used to study the habits, pedigree and main hereditary diseases of even a mummified Egyptian, even a mammoth. Now this diagnosis became commonplace in any molecular biology laboratory around the world.