Solvent modulation strategy for superior antibody monomer/aggregate separation in cation exchange chromatography.

•PEG as a mobile phase modifier improves the removal of mAb aggregates.•Addition of PEG alone is limited by decreasing protein solubility.•Solubility enhancers increase mAb solubility without elimination of the PEG effect.•The method is generically applicable and leads to superior mAb aggregate removal.