Under appropriate conditions of ionic strength, anion exchange (AEX) sorbents or membranes can be used in negative or flow-through mode. This is done to remove virus contamination which binds to the surface of the membrane whilst the therapeutic molecule of interest, such as a monoclonal antibody (mAb), passes through the device. The plug and play nature of membrane chromatography devices makes them particularly convenient for this type of polishing step.
Typically employed at the end of a sequence of chromatography steps, anion exchange membrane capsules can also help reduce levels of Host Cell Protein (HCP) and DNA contamination as well as provide an orthogonal approach to viral clearance. Pall Mustang® Q capsules can be especially effective in this regard and have been employed successfully as part of an orthogonal strategy for virus safety in several industrial processes.