EAH-Separopore® 4B is used to couple molecules containing carboxyl groups to the matrix for affinity chromatography. It was prepared by covalent coupling of 1, 6-diamino hexane to Separopore® 4B via epoxy activation. The free terminal amino group allows for coupling of carboxyl-group containing ligands through amide bond formation by carbodimide-mediated coupling method. Due to the long hydrophilic spacer arm (10-atom), bio-World’s EAH-Separopore® 4B is ideal for immobilization of small molecules which are stable in low pH and contain free carboxyl groups.