This contribution describes the first use of surface-initiated AGET (activators generated by electron transfer) ATRP (atom transfer radical polymerization) to prepare high-capacity adsorptive membranes for bioseparations. The present advancement greatly simplifies membrane development by overcoming the need for specialized catalyst handling and solution de-oxygenation steps that are required for standard ATRP methods. Furthermore, it enables modification to be done with ppm-level catalyst concentrations. Surface-initiated AGET ATRP from base cellulose membranes was used to prepare amine-based anion-exchange membranes. No precautions were taken to remove oxygen from the system, and catalyst concentrations were 50-200 ppm. A set of experiments was carried out to optimize the molar amount of reducing agent used in formulation. Catalyst concentration and polymerization time were used as independent variables to study the effects on protein binding capacity of the surface-modified membranes. Bind-and-elute measurements were done with an adsorptive membrane bed to measure dynamic protein binding capacities and to demonstrate the highly favorable transport properties of the membrane bed. (C) 2011 Elsevier B.V. All rights reserved.