Aminophenyboronic acid (APBA) carrying-gel beads were proposed as alternative sorbents for nucleotide isolation. For the preparation of two different types of gel beads with different surface characteristics, two hydrophilic monomers, 2-hydroxypropylmethacrylate (HPMA) and polyethyleneglycol methacrylate (PEGMA) were selected as the base materials. The spherical gel beads were obtained by the suspension copolymerization of HPMA or PEGMA with epoxypropyl methacrylate (EPMA) by using ethyleneglycol dimethacrylate (EGDMA) as the crosslinker. A boronic acid carrying ligand, m-aminophenylboronic acid (APBA) was covalently attached onto the both types of gel beads via the direct chemical reaction between epoxypropyl and amino groups. The equilibrium APBA binding capacities of HPMA and PEGMA gel beads were 47 and 34 mg g(-1), respectively. The reversible adsorption-desorption behavior of beta-nicotinamide adenine dinucleotide (beta-NAD) was investigated comparatively by using APBA carrying-HPMA and PEGMA based gel beads as sorbents in batch-fashion. While no-significant non-specific beta-NAD adsorption was observed onto the plain (i.e. non-derivatized) gel beads, the equilibrium beta-NAD adsorption capacities of APBA carrying-HPMA and PEGMA based gels were determined as 11 and 4 mg g(-1), respectively. The desorption yields higher than 90% could be achieved with both types of gels. The results indicated that the proposed materials could be efficiently used as pseudospecific-sorbent for nucleotide isolation. (C) 2002 Elsevier Science B.V. All rights reserved.