Ligands binding affinity antibodies.

Solid support material having covalently immobilized thereon an affinity ligand, said ligand comprising one or more group (s) functional (s) hydrophobic (s) and one or more group (s) functional (s) cation (s), where at least one hydrophobic functional group is separated from at least one cationic functional group by a distance through links between 5 A and 20 A, wherein said ligand consists of less than 5 residues and has a molecular weight of between 120 Da and 1,000 Da; and wherein the ligand comprises or consists of 3 residues covalently, X1-X2-X3, where such residues covalently linked are also covalently bonded to the linker L of L-PM entity, where PM is the solid support material, wherein X 1 is a natural or unnatural amino acid in a configuration D and / or L, or a residue of carboxylic acid comprising an optionally substituted aromatic group, wherein X2 is a natural or unnatural amino acid in a configuration D and / or L, or a residue of carboxylic acid comprising an optionally substituted aromatic group, with the proviso that X2 is not a threonine residue, and wherein X 3 is a natural or unnatural amino acid in a configuration D and / or L, or a residue of carboxylic acid comprising a group optionally substituted aromatic, wherein at least one of X1, X2 and X3 comprises a cationic functional group, and wherein at least one of X1, X2 and X3 comprises a hydrophobic functional group, wherein X 1 is selected from L-Arg, D-Lys, D-Phe, D-Pro, INA, PPC, DBHBA, 3HBA, 4HBA and SAA; where X2 is selected from L-Arg, L-Asn, D-Leu, D-Lys, D-Phe, D-Pro, L-Pro, AIB, AHX, INA, NLE and PPC; and where X3 is selected from L-Arg, L-Asn, D-Lys, D-Phe, D-Pro, L-Pro and PPC.