In-line buffer exchange in the coupling of Protein A chromatography with weak cation exchange chromatography for the determination of charge variants of immunoglobulin G derived from chinese hamster ovary cell cultures

•The solvents which effect elution in ProA and WCX chromatography are incompatible.•Solvent exchange is needed for 2DLC charge variant analysis of mAbs via ProA x WCX.•An in-line SEC column allows solid phase solvent exchange for the direct coupling.•The ProA x SEC x WCX method is validated using the NISTmAB.•The method is seen as an highly versatile approach to mAb characterization.