The concept of “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 both those and other characteristic chemical properties. 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 different participants and outcomes. And the biological property in question, which is of primary interest to physicians and scientists, is the ability of a microorganism to cause disease or death in a susceptible animal.
So what is it? The neutralization test is a serological test used in laboratory diagnostics, in which immune serum antibodies inhibit the activity of microorganisms, as well as the toxic and biologically active substances (enzymes) they release.
Applications
Most often this research method is used to identify viruses, that is, to diagnose viral infectious diseases. And the test can beis 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, antistreptokinases.
How this test is done
The neutralization reaction is based on the ability of antibodies - special immune blood proteins - to neutralize antigens - foreign agents that enter the body. If it is necessary to detect the pathogen and identify it, then a standard immune serum containing antibodies is mixed with biological material. The resulting mixture is kept in a thermostat for the right time and introduced into a living receptive system.
These are laboratory animals (rats, mice), chicken embryos, cell cultures. In the absence of a biological effect (illness or death of the animal), it can be concluded that this is exactly the virus for which the standard serum was used. Since, as already mentioned, a sign that the reaction has passed is the loss of bioproperties by the virus (the ability to cause the death of the animal) due to the interaction of serum antibodies and virus antigens. When determining 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 studying the latter, a control toxic substance is used. In order for the neutralization reaction to take place, this mixturethe predetermined time is also incubated and injected into the susceptible 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 carried out in the so-called paired sera technique.
This is a way to confirm the diagnosis of a viral disease. To conduct it, blood serum is taken from a sick person or animal twice - at the beginning of the disease and 14-21 days after that.
If, after the test, an increase in the number of antibodies to the virus by 4 or more times is detected, then the diagnosis can be considered confirmed.
