ELISA diagnostics

ELISA diagnostics of infections is a method of enzyme immunoassay , which is increasingly used in medicine. It is based on the detection in the patient's body of characteristic antibodies or on the detection of antigens of the causative agent of the disease.

Antigens are substances that, getting into the body, cause a protective reaction of the immune system, when infected, it starts producing special proteins - antibodies.

Each pathogen has its own set of antigens, having determined them, the doctor can make a "portrait" of the suspected microorganism. The immune system also works selectively and produces antibodies for a particular virus, and they will not interact with the antigens of another pathogen.

The mechanism by which ELISA diagnostics is possible is a reaction of antigens to the introduced antibodies, as a result of this reaction an antibody-antigen complex is formed. Where do antibodies or antigens come from for such a reaction? It's very simple, they are manufactured industrially for each type of research. Each type of antigens or antibodies is labeled at the plant with a special enzyme. Thus, with the formation of the antibody-antigen complex, it will have a label in its composition, and when the coloring reagent is added, thanks to the presence of this label, all the complexes that have arisen will change color.

When ELISA is used to diagnose the sample, the intensity of staining of antibodies and antigens in the material used in the diagnosis is investigated, and special equipment counts their number.

Results of ELISA

If antigens of the infection are found or antibodies to them, what does this mean? This means that the patient definitely has an infection. And IFA diagnostics can give the name of a specific microorganism responsible for the appearance of this antigen with high accuracy. Interestingly, unlike virological or bacteriological methods of diagnosis, the weak viability of the virus does not interfere with its definition.

But there is another side to this medal, if the ELISA diagnostics in the test sample showed antibodies that clearly indicate the patient's contact with the pathogen, this can not be a guarantee that the microorganism is still present in the human body. After all, antibodies can remain a fairly long time in the patient's body even after recovery. The negative result of ELISA with a single check for the presence of antibodies is also not always reliable. For the emergence of an immune response, the body takes time, which is why a second analysis is carried out for a precise diagnosis two to three weeks after the first. And that is why ELISA diagnostics of most of the known infections makes sense not earlier than three weeks after infection.

The advantages of immunoenzyme diagnostics of infectious diseases

The analysis by the methods of immunofermentation has a number of advantages, thanks to which it has become so popular in recent years.

With its help, it became possible to diagnose a wide range of various infections. For example, viral infections (cytomegalovirus, HIV, herpes, hepatitis), most sexually transmitted infections (mycoplasmosis, syphilis, chlamydia, ureaplasmosis), as well as borreliosis, tick-borne encephalitis and others.

Short term, for which it is possible to conduct a study, especially if it is required to identify the antigen of the pathogen or to determine the level of antibodies once. Typically, this type of analysis requires one to three days.

ELISA diagnostics can be used in cases where microscopy or cultivation is complicated or impossible at all.

It is able to assess the effectiveness of the immune response of the patient's body to the introduction of the pathogen.

Having identified the ratio of different classes of immunoglobulins, the physician will be able to determine at what stage the disease is at the moment, the importance of this information can not be overestimated.

All these advantages have made IFA diagnostics an indispensable assistant to modern medicine.