Reaction of neutralization, the essence of the method and practical application

The term "neutralization reaction" existing in inorganic chemistry implies a chemical process in which substances with acidic and basic properties interact, as a result of which the participants in the reaction lose the characteristic chemical properties of the reaction. The neutralization reaction in microbiology has the same global significance, its products lose their biological properties. But, of course, this is a completely different process with other participants and outcomes. And the biological property in question and which is primarily of interest to doctors and scientists is the ability of the microorganism to cause disease or death of a susceptible animal.

So, what is it? The neutralization reaction is a serological test used in laboratory diagnostics, in which antibodies of the immune serum inhibit the activity of microorganisms, as well as the toxic and biologically active substances (enzymes) released by them.

Areas of use

Most often this method of research is used to identify viruses, that is, the diagnosis of viral infectious diseases. Moreover, the test can be aimed both at identifying the pathogen itself and antibodies to it.

In bacteriology, this technique is usually used to detect antibodies to bacterial enzymes, such as antistreptolysins, antistaphylolysins, anti-streptokinases.

How this test is conducted

The neutralization reaction is based on the ability of antibodies - special immune proteins of the blood - to neutralize antigens - foreign agents that enter the body. If it is necessary to detect the pathogen and identify it, then the standard antibody serum containing antibodies is mixed with the biological material. The resulting mixture is aged in the thermostat at the right time and injected into a living, susceptible system. These are laboratory animals (rats, mice), chicken embryos, cell cultures. In the absence of biological action (illness or death of the animal), it can be concluded that this is the virus the standard serum to which it was used. Since, as already mentioned, a sign that the reaction has passed is the loss of the virus of the biological properties (the ability to cause the death of the animal) due to the interaction of serum antibodies and antigens of the virus. When determining the toxic substances, the algorithm of actions is the same, but there are options. If any substrate containing a toxin is examined, then it is mixed with standard serum. In the case of the latter, a control toxic substance is used. In order for the neutralization reaction to proceed, this mixture is also incubated for a given time and introduced to a receptive system. The technique for evaluating the result is exactly the same.

In medical and veterinary practice, the virus neutralization reaction used as a diagnostic test is performed in the so-called paired sera technique.

This is the way to confirm the diagnosis of a viral disease. To carry it out, a sick person or animal takes blood serum twice - at the beginning of the disease and 14-21 days afterwards.

If the test shows an increase in the number of antibodies to the virus 4 or more times, the diagnosis can be considered confirmed.