The rise in cancer, autoimmune, inflammatory, and infectious diseases in recent decades has led to a surge in the development of monoclonal antibodies (mAbs) therapies, now the most widely used family of biologics. To meet the growing global demand, biopharmaceutical industries are intensifying their production processes. One approach to achieve more efficient production of effective mAbs is to develop tools for real-time quality monitoring. Specifically, the glycosylation profile of mAbs must be closely monitored, since it greatly impacts their therapeutic efficacy and innocuity, making it a critical quality attribute. In this study, we developed a surface plasmon resonance-based integrated assay allowing for the simultaneous quantification and glycosylation characterization of mAbs in crude samples, hence permitting the at-line analysis of bioreactor cell cultures. Thanks to the high specificity of the interaction between biosensor surface-bound protein A and the Fc region of mAbs, we quantified crude IgG samples under mass transport limitations. Next, by flowing running buffer on the surface, impurities contained in the mAbs samples were washed away from the biosensor surface, allowing subsequent recording of the kinetics between the captured mAbs and injected FcγRII receptors. Of interest, with this strategy, we were able to quantify terminal galactosylation and core fucosylation of IgG lots, two important glycan modifications for mAb efficacy.