The identification of pathogens is accompanied by the delivery of tests. We hardly read strange words in the direction. Often there is such a method of laboratory diagnostics as polymerase chain reaction. What is PCR? Let's get it right.
Story
The method was created by Cary Mullis in 1983. For him, the scientist was awarded the Nobel Prize. Initially, the method was planned for use for scientific purposes, but, having examined its effectiveness and prospects, they began to promote innovation in practical medicine.
Sometimes to the question: “What is PCR?” they say that this is a technique for finding a needle in a haystack. Here, by a needle is meant a fragment of the genetic material of a microorganism, and hay - a human body.
Principle of operation
In the body, DNA is responsible for genetic information. Nucleotides of adjacent helices are connected in the established order. Every living organism has its own DNA - it doesn’t matter if it is a person, an animal, a virus or a bacterium. To identify the body, you need a small area of the genetic repository. It happens that microorganisms (immunodeficiency virus) store information in ribonucleic acid, but this method also finds fragments of it.
You still do not understand what PCR is and how it works? Know, its principle is based on the discovery of a unique site. Indeed, for all pathogens, there are specific genetic detectors, reference DNA fragments. They pick up "their piece" and trigger the reaction of creating copies.
In three minutes (one cycle), the number of copies grows significantly. And in a few hours, the number of fragments increases billions of times. Therefore, the causative agent of infection can be easily identified.
Answering the question of what PCR is, one cannot help but mention the pros and cons of this method.
Advantages:
Universality. When other methods are powerless, PCR analysis is powerful. It detects any RNA and DNA on standard equipment.
High specificity. The nucleotide sequence is characteristic of only one specific pathogen. That is, the guarantee is 100%. Also, the studied material can be aimed at identifying several microorganisms simultaneously. The quality of the answer does not suffer from this.
Sensitivity. You can find the smallest fragment of a microorganism.
Efficiency PCR is a diagnosis in a few hours. From the delivery of the material to the receipt of the result, no more than one day is needed.
Determination of the pathogen in the incubation period. Even if there are no visible signs of the disease, the method will be able to diagnose the pathogen and determine the disease.
disadvantages
"PCR - what is it?" - Ask the uninformed. But we already know that this is an effective method of searching for an infectious pathogen. Unfortunately, it also has drawbacks. For example, there is a “false response”, because in the air there is a cocktail of DNA fragments of many living organisms - and during the reaction, the sample may be “contaminated”. To prevent this, a biological treatment filter is installed in the room.
Evaluate the results of the analysis should be a specialist. Since a positive answer does not always mean the presence of a disease. Some residual pathogens after treatment live in the body for several months without causing harm. A low caption shows that in life a person once encountered this microorganism.
A negative analysis in the presence of an obvious picture of the disease indicates that the material was taken incorrectly (not from there or not according to the instructions).
If you doubt the results of the analysis, retake them by another method or in another laboratory. The combination of several methods gives a 100% assessment of the body for the presence or absence of infectious pathogens. And remember: all the results of laboratory tests need to be shown to the doctor. Do not draw independent conclusions or diagnose yourself!