Antigen Excess Zone

The zone of antigen excess is the range of quantitative ratios of antigens and antibodies in the reactions of precipitation and complement fixation, in which a relative excess of antigens is observed.

This zone is characterized by the formation of complexes that do not completely precipitate and have low complement-binding activity.

This excess of antigens leads to the fact that all antibodies are associated with antigens, but some of these complexes remain soluble. This is due to the fact that each antibody molecule can bind to only one determinant on the antigen molecule.

With a large excess of antigens, some of their determinants remain free, which prevents complete aggregation and precipitation of immune complexes. Thus, the zone of antigen excess reflects a state where the concentration of antigen exceeds the concentration of antibodies.

The antigen excess zone is the range of quantitative relationships between antigens and antibodies in reactions characterized by a relative excess of antigens. In this zone, the formation of complexes is observed, which do not completely precipitate in the form of precipitates and have low complement-binding ability.

The zone of antigen excess is important for understanding the mechanisms of the immune response and its regulation. It describes a condition when the amount of antigen exceeds the amount of antibodies, which leads to the formation of excess antigens on the surface of cells. This can lead to the activation of target cells and trigger an immune response.

Several features are observed in the zone of excess antigen. Firstly, complexes of antigens with antibodies do not precipitate in the form of precipitates, which is associated with an excess of antigen. Secondly, the complexes have low complement-binding ability, which indicates the lack of complete binding of antibodies to antigens.

In addition, the zone of antigen excess can be used to determine the activity of antibodies and evaluate their effectiveness in combating infectious agents. If antibodies can effectively bind to antigens in the area of ​​excess, this indicates their high activity and ability to protect the body from infection.

Thus, the zone of antigen excess is an important concept in immunology and can be used to assess antibody activity and understand the mechanisms of the immune response to antigens.