Ion-exchange chromatography is widely used for the purification of biotherapeutic proteins. Usually, cation exchangers are applied in the primary capture step of proteins with alkaline pI. Conventional ion-exchange chromatography has the advantage of high-binding capacity, but it requires low salt conditions for protein binding and consequently adjustment of conductivity of clarified culture supernatant. An alternative method to maintain some binding capacity at higher conductivity levels is working at low pH condi¬tions notwithstanding that some proteins are sensitive to acid treatment.…