In pharmaceutical applications, the purity and efficacy of plasmid DNA (pDNA) as a therapeutic product are stringent. The separation of linear, supercoiled (sc), and open-circular (oc) pDNA isoforms has already been established on CIM® butyl (C4 HLD) monolithic columns at a preparative scale. This process requires a high concentration of ammonium sulfate for loading, which increases the overall production requirements. Competing adsorption in sample displacement chromatography utilizes the chromatographic resin's binding capacity more efficiently and increases the chromatographic step's productivity.
This application note investigates three monolithic chromatographic supports with different hydrophobicities regarding their applicability for sample displacement of pDNA. CIMac™ C4 HLD (butyl, high ligand density) as a commercial product and pyridine and histamine as custom immobilised columns are compared.