In this study, we developed a tailored capillary with human serum albumin (HSA) as bioligand for affinity for bilirubin removal. Capillary was introduced with epoxy groups by using radiation-induced graft polymerization. Microporous membranous polytetrafluoroethylene (MPTFE) capillary and common polytetrafluoroethylene (CPTFE) capillary were used. The effects of the flow rate, temperature, ionic strength and pH value were investigated. Optimal adsorptions could be achieved in a suitable flow rate and appropriate temperature. Comparison with other bilirubin adsorbents shows that the human serum albumin immobilized capillaries has not only a high-affinity adsorption capacity (up to 71.2 and 53.8 mg bilirubin/g polymer for MPTFE and CPTFE, respectively) towards bilirubin molecules but also a shorter adsorption equilibrium time (about 60 and 70 min for MPTFE and CPTFE, respectively). This new adsorbents has both the advantage of membrane and micro-column, and it has mass transfer of higher velocity, better adsorption capacity, less fouling, longer useful life. And this system is low cost and easy to operate. The results of blood tests suggested the HSA affinity capillary has good blood compatibility. (c) 2006 Elsevier B.V. All rights reserved.