MabSelect VH3 Protein A affinity resin effectively separates antibody species containing different numbers of VH3 domain and shows improved aggregate separation capability.

MabSelect VH3 is a new Protein A resin recently launched by Cytiva. According to the manufacturer, the Protein A ligand of MabSelect VH3 has been engineered to disrupt and reinforce its Fc and VH3 binding capabilities, respectively. Thus, different from regular Protein A resins, this new Protein A resin has affinity for VH3 domain only. The vendor has suggested that MabSelect VH3, owing to its unique selectivity, can separate byproducts that are different from the product in the number of VH3 domain. In the current work, with two concrete cases, we demonstrated that MabSelect VH3 indeed allows effective separation of species containing different numbers of VH3 domain. In addition, we showed that, in comparison to regular Protein A resins, MabSelect VH3 also exhibits improved aggregate separation potential. Thus, for cases where product and byproduct differ in the number of VH3 domain and/or culture harvest contains high percentage of aggregates, MabSelect VH3 is a better alternative than regular Protein A for product capture as it allows simultaneous removal of byproducts and aggregates.