Purity, aggregation and target binding are critical quality attributes that need to be monitored throughout the antibody development cycle, as they impact product efficacy and safety. Yet, traditional chromatographic technologies for their assessment were primarily established for monoclonal antibody (mAb) IgG formats and can be difficult to optimize for larger IgM complexes or newer bispecific antibody (bsAb) formats. ​

Mass photometry is a modality-agnostic technology that can assess aggregation and target binding in different antibody formats after a simple one-step optimization. Mass photometry measures the mass of individual particles in solution with native buffers in minutes, using only nanograms of sample.​

In the first part of this webinar, we compare the performance of mass photometry and SEC-HPLC in the determination of antibody purity and aggregation in different antibody formats. In cases where meaningful data could be obtained from SEC-HPLC, mass photometry measurements agreed with the SEC-HPLC data. In addition, being a single-particle technique, mass photometry provided superior resolution on oligomeric states. In other cases, meaningful data could not be obtained from SEC-HPLC, but mass photometry was able to quickly and reliably assess antibody purity/aggregation.​

In the second part, we delve into antibody-antigen binding mechanisms of mAbs and bsAbs. We show how mass photometry can measure binding stoichiometry and binding affinities associated with the different stoichiometries.​