We investigated the effect of an amphiphilic comb polymer on reducing nonspecific adsorption of biomolecules in membrane filtration. The amphiphilic comb polymer is a methyl methacrylate-based coating material with short nonfouling oligoethylene glycol side chains that provides long-term, bio-repellant surfaces. The nonfouling property of this polymer on a commercially available filtration membrane was observed through cyclic filtration-washing processes of microbial, alginic acid, and bovine serum albumin solutions. The chemical structure and properties of the synthesized comb polymer were determined by Fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and gel permeation chromatography (GPC), while the permeation characteristics of the hydrophobic polysulfone membrane and comb polymer coated membranes were examined using home-built ultrafiltration cross-flow sets. Membranes coated with the comb polymer showed higher flux recovery than control membranes after a five-cycle filtration-washing process. Taken together, this shows that the comb polymer effectively inhibits the fouling of membrane surfaces by biomolecular materials. (c) 2006 Elsevier B.V. All rights reserved.