An affinity membrane that could be used for isolation of ribonucleic acid (RNA) from nucleic acid mixtures was synthesized by the radical copolymerization of 2-hydroxyethylmethacrylate (HEMA) with 4-vinylphenylboronic acid (VPBA). Potassium persulfate (KPS) and N,N,N',N'-tetramethylethylenediamine (TEMED) were the redox initiator pair and N,N-methylenebisacrylamide (MBA) was the crosslinker in copolymerization conducted at room temperature (22 degreesC). The effects of inclusion of VPBA on hydrophilicity and porosity of the main monomer, i.e., HEMA, were tested by swelling runs and scanning electron microscope (SEM) micrographs. Two poly(HEMA-co-VPBA) membranes with different VPBA contents and poly(HEMA) as a reference material were tested for RNA isolation. RNA adsorption capacities of functionalized membranes were determined as 8.72 mg RNA g(-1) in case of membrane with low VPBA content and 16.0 mg RNA g(-1) with high VPBA membrane while that for poly(HEMA) was zero. The non-specific deoxyribonucleic acid (DNA) adsorption capacity of all membranes was nearly 4.0 mg DNA g(-1). The desorption yields in 1 h release period were over 85% in borate buffer (pH 8.5) including 0.5 M NaCl. (C) 2003 Elsevier Science B.V. All rights reserved.