The concept of “neutralization reaction” existing in inorganic chemistry implies a chemical process in which substances with acidic and basic properties interact, resulting in the loss of reaction participants of both these 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 other participants and outcomes. And the biological property in question, which is primarily of interest to doctors and scientists, is the ability of a 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 toxic and biologically active substances (enzymes) secreted by them.
Areas of use
Most often, this research method 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, antistreptokinases.
How is this test conducted?
The neutralization reaction is based on the ability of antibodies - specific immune proteins of the blood - to neutralize antigens - foreign agents that enter the body. If pathogen detection and identification is necessary, then standard immune serum containing antibodies is mixed with biological material. The resulting mixture is kept in a thermostat for the right time and is introduced into a live susceptible system.
These are laboratory animals (rats, mice), chicken embryos, cell cultures. In the absence of biological action (illness or death of an animal), we can conclude that this is the virus whose standard serum was used. Since, as already mentioned, a sign that the reaction has passed is the loss of biological properties (the ability to cause death of an animal) by the virus 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 proceed, this mixture is also incubated for a predetermined time and introduced to 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 serum technique.
This is a way to confirm the diagnosis of a viral disease. To carry it out, a 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.