A measure of the binding constant of a single -combining site with a monovalent antigenic .
The average affinity of a secreted antibody and of membrane on antigen-specific increases following
antigenic stimulation and is substantially higher in secondary than in primary antibody responses. This occurs
due to small mutations in the DNA coding for IgV regions in individual antigen stimulated B lymphocytes.
The property of antibodies which enables them to react with some antigenic determinants and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.