ABSTRACT
INTRODUCTION An early characterization of biopharmaceuticals (proteins) is needed to evaluate the comparability of materials, which is more complicated due to the inherently heterogeneous nature of many biologicals. This includes factors such as microheterogeneity of glycosylation, differential proteolytic processing during cellular production, or variations in post-translational modifications, factors which are not common to small molecule characterization and evaluation for interaction. This requires availability of highly specific discriminating methodologies, such as spectrophotometric, chromatographic, electrophoretic methods, and mass spectroscopy (MS), often combined with liquid chromatography (LC).
