DNA adsorption onto polyethylenimine-attached poly(p-chloromethylstyrene) beads

In this study, DNA adsorption properties of polyethylenimine (PEI)-attached poly(p-chloromethylstyrene) (PCMS) beads were investigated. Spherical bead s with an average size of 186 mum were obtained by the suspension polymeriz ation of p-chloromethylstyrene conducted in an aqueous dispersion medium. O wing to the reasonably rough character of the bead surface, PCMS beads had a specific surface area of 14.1 m(2)/g. PEI chains could be covalently atta ched onto the PCMS beads with equilibrium binding capacities up to 208 mg P EI/g beads, via a direct chemical reaction between the amine and chlorometh yl groups. After PEI adsorption with 10% (w/w) initial PEI concentration, f ree amino content of PEI-attached PCMS beads was determined as 0.91 mequiv. /g. PEI-attached PCMS beads were utilized as sorbents in DNA adsorption exp eriments conducted at +4 degreesC in a phosphate buffer medium of pH 7.4. D NA immobilization capacities up to 290 mg DNA/g beads could be achieved wit h the tried sorbents, This value was approximately 50-times higher relative to the adsorption capacities of previously examined sorbents. (C) 2000 Els evier Science B.V. All rights reserved.