Adsorption of proteins on solid surfaces is widely studied because of its importance in various biotechnological, medical, and technical applications, e.g., biosensors, cardiovascular implants, and chromatography. Adsorption thermodynamics has been studied on the microbeads of N,N'-diethylaminoethyl (DEAE) Dextran anion exchanger for the human serum albumin (HSA) at 25, 30, 35, 40, and 45 degrees C. As a result, some thermodynamic parameters like Freundlich constants, thermodynamic equilibrium constant (K-D), standard free energy changes (Delta G(assoc)), standard entropy changes (Delta S-assoc), and standard enthalpy change have been evaluated. Using the linear Van't Hoff plot, Delta S-assoc value of the system for the interaction of bovine serum albumin (BSA)-adsorbed crosslinked DEAE dextran microbeads was determined as 20.650 kJ/mol. (c) 2006 Wiley Periodicals, Inc.