Points on importance of ligands in affinity chromatography are: Ligands in affinity chromatography are important because they control selective binding and maintain specific retention of target molecules. Ligands are chosen to match the biological or chemical properties of the target molecule, allowing only specific molecules to bind to the stationary phase. Selective binding occurs because ligands interact with targets through defined mechanisms such as antigen–antibody, enzyme–substrate, or receptor–ligand interactions. Molecules lacking complementary binding sites do not interact with the ligand and therefore pass through the column without retention. The specificity of ligand–target interaction determines which component of a mixture is captured during the separation process. Once bound, the ligand holds the target molecule on the stationary phase under controlled buffer and flow conditions. Specific retention prevents the target molecule from eluting with non-binding or weakly int...