Immunoaffinity chromatography is a form of liquid affinity chromatography in which an antibody, antibody fragment, antigen, or closely related immunoreagent serves as the immobilized recognition ligand. A complementary target binds through reversible antigen–antibody recognition while nonbinding components pass through or are removed by washing ^[1]. The captured species is released by conditions that weaken noncovalent binding, such as controlled changes in pH or ionic strength or addition of a competing epitope, without cleaving the immobilization linkage. Selectivity depends on antibody affinity and cross-reactivity, ligand orientation and surface density, support accessibility, and mass transfer ^[2]. The method is a chromatographic bed or flow-through device and is therefore distinct from immunoprecipitation in a freely suspended solid phase. It is also narrower than general affinity chromatography because the recognition pair is immunological. Essential features are an immobilized immunoreagent, reversible and specific target capture, washing that preserves the complex, and an elution or detection step that reports the retained target.