The unique protein-binding property and strong byproduct separation capability of salt-tolerant anion exchanger TOYOPEARL NH2-750F.

TOYOPEARL NH2-750F is a salt tolerant anion exchange (AEX) resin from Tosoh, which is designed for intermediate purification of mAbs and other types of biomolecules. It is composed of polymethacrylate beads that have been functionalized with primary amine (NH2) AEX groups. Unlike conventional AEX resins, NH2-750F resin can maintain its capacity at conductivities up to 15 mS/cm when used in bind-elute mode. In a sense, NH2-750F is similar to mixed media as both electrostatic and hydrophobic interactions contribute to protein retention. A remarkable difference between NH2-750F and conventional AEX also lies in the fact that certain proteins can bind to the former but not the latter at pHs below their isoelectric points (pIs). According to its manufacturer, NH2-750F shows improved selectivity for protein monomer. In the current work, with two case studies, we demonstrate that NH2-750F possesses unique protein-binding property and good byproduct separation potential, which distinguishes itself from conventional AEX and AEX-dominated mixed-mode resins. This resin's strong byproduct separation capability and moderate price make it an attractive tool for intermediate and polishing purification.