Protein Analysis

In-depth protein analysis in accordance with the ICH Q6B guidelines including structure, physicochemical properties, potency, impurities and concentration

Proteins can present significant analytical characterization challenges. To ensure product quality and consistency, our biopharmaceutical analysis experts provide protein, peptide, glycoprotein and protein conjugate analysis services which are offered in accordance with the requirements of the ICH Q6B Guidelines, Specifications: Test Procedures and Acceptance Criteria for Biotechnological / Biological Products. 

Intertek's capabilities help to address the requirements for a "well characterized" or specified biological drug product or drug substance and include thorough product characterization during development, raw material testing, in-process testing, stability testing and batch release testing.  

Structural Characterization and Confirmation:

  • Amino-acid sequence
  • Amino-acid composition
  • Terminal amino acid sequences:
    • N-terminal sequences by LC-MS/MS sequencing of peptide fragments from digests
    • C-terminal sequences by LC-MS/MS sequencing of peptide fragments from digests
  • Peptide map - peptide mapping using enzymatic or chemical fragmentation followed by mass spectrometry (MALDI-TOF or electrospray MS)
  • Disulphide bridge (S-S bridge) maps by mass spectroscopy (MALDI-TOF or Electrospray MS)
  • Glycosylation Studies by enzymatic glycan cleavage and fingerprinting by ion chromatography (IC) or MALDI-MS
  • Post Translational Modification Studies (PTM) using a broad range of digest strategies and LC-MS/MS (including enhanced scan techniques)
  • Positions of conjugation e.g. protein-toxin conjugates using LC-MS and LC-MS/MS to determine loading and binding sites
  • Carbohydrate Content (neutral sugars, amino sugars and sialic acids), 
  • Glycosylation Studies using multiple cycles of selective enzymatic cleavage and MALDI-TOF to build up a detailed picture of carbohydrate chains, oligosaccharide pattern (antennary profile) and the glycosylation site(s) 

Physicochemical properties:

  • Molecular weight (or size) by mass spectrometry, chromatography and electrophoresis approaches (MALDI-TOF, ESI-MS, LC-MS, SEC / GPC, SDS-PAGE)
  • Isoform pattern and impurity studies using chromatography and or gel / capillary electrophoresis (PAGE, SDS-PAGE, IEF, CE, HPLC)
  • Extinction coefficient determination and validation
  • Electrophoretic patterns for identity, homogenity and purity by SDS-PAGE, IEF, WB, CE
  • Liquid chromatographic patterns (RP-HPLC,  Ion Exchange HPLC and Size Exclusion Chromatography)
  • Spectroscopic profiles by UV-vis, circular dichroism (CD), NMR and FTIR (higher order protein structure)


Advanced protein analysis services:

Need help or have a question? +1 800 967 5352

Need help or have a question?

+1 800 967 5352
+44 161 721 5247
+41 61 686 4800