Typically, several analyses are combined to characterize protein size, structure, and physiochemical properties completely. These include intact mass and peptide fragmentation analysis, distribution of post-translational modifications, amino acid sequence verification, and additional peptide mapping as necessary. In addition, we recommend thorough protein impurity and stability analysis for a complete overview of your drug product’s quality attributes. For mAbs, we analyze the light and heavy chains (intact and reduced) separately, providing an overview of the variable regions (VJ and VJD) even if the B-cell hybridoma is unavailable.