This month, Lester Taylor, director of LC-MS product marketing, and Ning Tang, senior application scientist (both at Agilent Technologies) talk about the advances that have extended adoption of mass spectrometry (MS) in QA/QC laboratories. Ideal technologies for analyzing large proteins and peptides include high-resolution LC-MS time-of-flight (TOF) spectrometry and hybrid LC-MS quadrupole TOF (Q-TOF) methods. The experts also discuss software tools for MS analysis, which facilitate the processing of complex data sets. Traditional biopharmaceutical applications for MS include protein molecular-weight confirmation, peptide mapping, and glycan analysis. Tang and Taylor review those (and other) uses along with associated challenges. Non-LC methods are also discussed, including capillary electrophoresis MS (CE-MS) for molecule characterization. Finally, the experts provide their perspectives on future MS applications and advancements.