Purification of plasmid DNA with a new type of anion-exchange beads having a non-charged surface
We have prepared a new type of anion exchanger, which effectively discriminates between RNA and plasmid DNA. The material is based on a Sephacryl S-500 HR matrix provided with quartenary amine anion-exchange groups. A distinguishing feature of the beads is that a thin (2-3 mum) outer layer of the beads lacks ion-exchange groups. In the synthesis of these beads the vinyl groups in the outer layer o
