The effect of in-place regeneration of dye-ligand adsorbents on protein adsorption characteristics is presented. Regeneration with chemical treatments and time of exposure determined the protein capacity of the adsorbent, but no effect was observed on its protein binding affinity. Fixed-bed adsorption of bovine serum albumin and its selectivity with respect to lysozyme was studied. Breakthrough curves were measured for protein adsorption on fixed-bed columns and analyzed by a simple model to determine the relevant rate constants for the adsorption process. It was found that forward adsorption rate constant increased exponentially with the chemical treatment exposure time. Column linear gradient elution studies showed that adsorbent selectivity decreased with the chemical treatment exposure time due mainly to column loss of adsorption capacity. The implications of the results on the design and optimization of dye-ligand chromatographic processes are discussed.