agglutination

physiology

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Last updated

June 17, 2026

Quick Summary

In physiology, agglutination is a process where particles, such as bacteria or red blood cells, clump together. This occurs when a substance called an agglutinin, typically an antibody, reacts with a specific surface structure called an antigen on these particles.12

This reaction causes the suspended particles to adhere to each other, forming visible clumps. Agglutination is a highly specific and reversible antigen-antibody reaction.1

The presence of agglutinins in blood serum can be used to detect past or present infections or immunizations, as well as to identify specific types of bacteria or red blood cells. A well-known example is in blood typing, where the presence or absence of specific antigens (A and B) and agglutinins (anti-A and anti-B) determines an individual's blood group.1

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blood group
The importance of antigens and antibodies
…antibodies usually results in clumping—agglutination—of the red cells; therefore, antigens on the surfaces of these red cells are often referred to as agglutinogens.
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…antibodies usually results in clumping—agglutination—of the red cells; therefore, antigens on the surfaces of these red cells are often referred to as agglutinogens.
Read More