Boronic acid carrying (2-hydroxyethylmethacrylate)-based membranes for isolation of RNA

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 °C). 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.