DNA-responsive uniform latex particles based on p-chloromethylstyrene

In this study, DNA binding properties of poly(ethylenimine) (PEI)-attached uniform poly(p-chloromethystyrene) (PCMS) particles were investigated. Sphe rical PCMS latex particles with an average size of 1.75 mum were obtained b y the dispersion polymerization of p-chloromethylstyrene (CMS). PEI was cov alently attached onto the PCMS particles via a direct chemical reaction bet ween amine and chloromethyl groups, with the equilibrium binding capacities up to 41 mg PEI/g PCMS. In aqueous media, PEI attached-uniform PCMS partic les showed an irreversible aggregation behaviour in the presence of DNA. To predict unknown DNA concentration, the aggregation response of these parti cles to the presence of DNA was quantified by spectrophotometry. Plain PCMS and PEI attached-uniform PCMS particles were also utilized as sorbents in DNA adsorption experiments conducted at +4 degreesC in a phosphate buffer m edium at pH 7.4. DNA immobilization capacities up to 45 mg DNA/g PCMS could be achieved with the PEI attached particles.