Affinity dye-ligand, Cibacron Blue F3GA, was covalently coupled with aminated chitosan microspheres via a nucleophilic reaction. The maximum attachment of Cibacron Blue F3GA was 494 mu mol/g. Albumin adsorption onto both unmodified chitosan (CS) microspheres and Cibacron Blue F3GA-attached chitosan (CBF-CS) microspheres was investigated batchwise. The bovine serum albumin (BSA) adsorption capacity of the CBF-CS significantly increased (95.2 mg/g dry bead) compared with the adsorption by CS (12.7 mg/g dry bead). The adsorption equilibrium isotherms appeared to follow a typical Langmuir isotherm. The maximum adsorption capacity (q(m)) of the CBF-CS microspheres for BSA was 108.7 mg/g. The highest desorption ratio (over 99%) was achieved by using 1.0 M NaSCN (pH 8.0). The CBF-CS microspheres could be reused without significant decreases in the adsorption capacities. (C) 2005 Elsevier B.V. All rights reserved.