https://doi.org/10.1351/goldbook.09661
Strength of association between a single antibody and a single epitope of antigen.
Notes:
- Affinity of the immunochemical reaction: \[\ce{Antibody + Antigen -> Antibody{-}Antigen}\] is characterised by the affinity (binding, association) constant \[K_{\rm{A}} = [\ce{Antibody{-}Antigen}]/[\ce{Antibody}][\ce{Antigen}]\]
- The average binding constant reflects a population of antibody molecules (polyclonal antibody).