(436d) Selective Displacement Chromatography in Multi-Modal Systems: Creating Unique Windows of Selectivity in Protein Separations
Previous studies have demonstrated the utility of selective displacement chromatography as an effective tool for the purification of biomolecules. In this paper we investigate the application of this technique on different multi-modal matrices. A robotic liquid handling system was employed to carry out a parallel batch screen of selective displacers on multiple protein pairs. The affect of different mobile phase modifiers were also investigated in this screen. By incorporating different combinations of chemistries into the design of the displacer (e.g. charge, metal chelation, hydrophobicity and hydrogen bonding) we were able to target specific interaction sites on the multi-modal resins, thereby augmenting the selectivity of the separation. Appropriate concentrations of complementary mobile phase modifiers were also shown to significantly enhance the selectivity of the displacement separation. Column displacements based on the batch screening results were then carried out on a select number of protein pairs and displacers to demonstrate the utility in the column mode. Finally, this approach was applied to industrially relevant mixtures for the removal of key impurities. These results demonstrate the ability of selective displacement chromatography to combine the selectivities of multi-modal resins, mobile phase modifiers and displacers to create a unique selectivity window unattainable using traditional modes of operation.