This article discusses the use of a com. resin to produce GMP-grade pDNA for clin. studies.PlasmidSelect Xtra chromatog. resin from GE Healthcare was assessed as part of an internal development program, the aim of which was to improve process robustness and resolution of key contaminants from the plasmid product.Initial studies focused on introducing the GE resin as an addnl. polishing step to the existing platform process.Following the success of this work, studies were performed to identify whether it was possible to streamline the platform process to a two-step purification process that includes the PlasmidSelect Xtra resin.PlasmidSelect Xtra resin is based on thiophilic aromatic chromatog., which can sep. plasmid from host contaminants and provides good resolution between open- and closed circle forms of plasmid DNA.