Amino Acid Sequence
- NH2-terminal sequencing and peptide mapping/MS.
Post-Translational Modifications / Degradation
- N-glycan profiling, peptide mapping/MS (glycosylation, glycation, phosphorylation, sulfation, deamidation and oxidation), ion exchange-HPLC (sialylation, sulfation and deamidation) and Ellman’s assay (unpaired Cys residues).
Purity
- SDS-PAGE, Western blot, size exclusion-HPLC, reversed phase-HPLC.
Aggregation/Structural Stability
- Near- and far-UV CD, intrinsic Trp fluorescence, structural melting curve, limited protease cleavage, multi-angle laser light scattering (MALLS), size exclusion-HPLC, SDS-PAGE.
Bioactivity
- In vitro binding by ELISA and Biacore.
Production Titer
- Protein A-HPLC for Abs and Fc-fusion proteins, product-specific ELISA and reversed phase-HPLC.