agglutinin ag·glu·ti·nin (ə-glōōt'n-ĭn)
A substance, such as an antibody, that is capable of causing agglutination of a particular antigen, especially red blood cells or bacteria.
A substance, other than a specific agglutinating antibody, that causes organic particles to agglutinate.
substance that causes particles to congeal in a group or mass, particularly a typical antibody that occurs in the blood serums of immunized and normal human beings and animals. When an agglutinin is added to a uniform suspension of particles (such as bacteria, protozoa, or red cells) that contains the specific surface structure (antigen) with which the agglutinin reacts, the suspended objects adhere to each other, form clumps, fall to the bottom, and leave the suspending diluent clear. This phenomenon of agglutination is a typical antigen-antibody reaction-highly specific, reversible, and involving small reacting groups on the surface of each.
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