Mixed-Mode Chromatography

Mixed-Mode Chromatography describes a separation technique combining multiple interaction mechanisms, typically ion exchange with hydrophobic interactions or hydrogen bonding, enabling enhanced selectivity and impurity removal compared to single-mode chromatography. Unlike conventional chromatographic resins that rely on one dominant binding mechanism, mixed-mode media provide versatile retention behaviours that can be tuned by adjusting pH, salt concentration, and buffer composition.

The biopharmaceutical industry increasingly employs mixed-mode chromatography in downstream purification of proteins, monoclonal antibodies, and viral vectors where high purity requirements demand robust multi-step processes. Mixed-mode resins can reduce process complexity by replacing multiple polishing steps, improving yield and reducing manufacturing costs. Process development focuses on optimising binding and elution conditions to achieve desired selectivity while maintaining product stability and activity. Mixed-mode chromatography supports impurity clearance strategies critical for regulatory compliance, particularly for biologics where subtle variants may impact safety and efficacy. As purification demands increase for complex modalities and continuous processing advances, mixed-mode chromatography continues evolving as a valuable tool enabling efficient, high-resolution separation.