Avidity

The avidity (Latin avidus, " greedy" ) of an antibody is the strength of a multivalent binding between antigen and antibody. This binding may be specific or multi -specific. Multi Specifically, it is when an antibody with different antigenic determinants reacting ( cross-reactivity ).

Monovalent interactions have a low, a high bivalent and polyvalent a very high avidity.

To differentiate is the avidity of the affinity of an antibody: affinity (expressed by the dissociation constant ) and the avidity is the set of affinities the force of a single antigen -antibody binding. The avidity between a monovalent antigen and a bivalent antibody is thus identical with the affinity.