Oxidation of a Glycosylated Therapeutic Protein


Protein characterization is at the heart of KBI’s service offerings. We offer a comprehensive range of analytical, biophysical, mass spectrometry, and biological assay capabilities. KBI’s scientists expertly apply these technologies and interpret the data to deliver the right information needed to support your product through all stages of development.

Protein_Characterization_smWhether you are seeking developability data to support proof-of-concept, initial characterization to support IND filing, or comprehensive forced degradation and impurity characterization to support BLA licensure, KBI offers the experience and instrumentation needed to enhance your understanding of your molecule and accelerate development.

KBI has substantial experience in the design and execution of analytical comparability studies. We have executed such studies in support of reference material characterization, manufacturing site changes, and biosimilar-to-innovator comparability, just to name a few. KBI will develop the protocol, perform the analyses, analyze the data, and provide a submission-ready comparability report with all requisite figures and tables.

Examples of KBI’s protein characterization capabilities include:

Protein Primary Structure

  • Peptide Sequencing via LC/MS/MS
  • Amino Acid Analysis
  • Peptide Mapping

Biophysical Characterization

  • CD, FTIR, DSC, DLS, MALS, fluorescence spectroscopy

Glycan Analysis

  • Oligosaccharide mapping
  • Monosaccharide composition
  • Sialic Acid Quantitation


  • Size Exclusion, including SEC-MALS
  • Ion Exchange
  • Reverse Phase
  • Hydrophobic Interaction
  • Affinity

Capillary and Slab Gel Electrophoresis

  • CZE
  • cIEF and icIEF
  • SDS-PAGE and IEF
  • Western blot
  • Microchip electrophoresis
  • 2D gels and blots

Process Residuals

  • ELISA (HCP, protein A etc.)
  • HPLC (antibiotics, IPTG, detergents, etc)
  • qPCR (DNA)

Potency Assays

  • Enzymatic activity
  • Binding Assays via ELISA, Biacore and ForteBio
  • Cell Based Assays (e.g., proliferation, cytokine release, etc.)

Particulate Analysis, including <10 micron particle characterization

  • HIAC
  • MFI
  • DLS

Mass Spectrometry

  • Intact mass
  • Peptide mapping with LC/MS or LC/MS/MS
  • Disulfide Mapping
  • Post translational modifications (e.g., oxidation, deamidation)
  • PEGylation site identification
  • Glycan Identification & site identification