--- type: "WebPage" title: "Protein Characterization in a Laboratory (ICH Q6B guideline)" description: "Protein Charactezation, what are we talking about ? In the development of biotechnological products (monoclonal antibodies, biosimilars, recombinant proteins), characterizing the molecule is not just a scientific challeng, it is a regulatory mandate.The ICH Q6B guideline requires a comprehensive understanding..." resource: "https://filab.fr/en/sectors-of-activity/biopharmaceutical/protein-characterization-ich-q6b-laboratory/" tags: ["EN", "Anaïs DECAUX"] timestamp: "2026-02-18T09:50:55Z" published: "2026-02-18T09:36:00Z" language: "en" author: "Filab" --- # Protein Characterization in a Laboratory (ICH Q6B guideline) ## Protein Charactezation, what are we talking about ? In the development of biotechnological products ([monoclonal antibodies](https://filab.fr/en/sectors-of-activity/biopharmaceutical/biotherapeutic-recombinant-protein-characterization/analysis-characterization-monoclonal-antibodies-mabs.md), [biosimilars](https://filab.fr/en/sectors-of-activity/biopharmaceutical/biotherapeutic-recombinant-protein-characterization/analysis-characterization-biosimilars.md), [recombinant proteins](https://filab.fr/en/sectors-of-activity/biopharmaceutical/biotherapeutic-recombinant-protein-characterization.md)), characterizing the molecule is not just a scientific challeng, it is a regulatory mandate. The **ICH Q6B**guideline requires a comprehensive understanding of the structural, physicochemical, biological, and immunochemical properties of the drug substance. **FILAB**supports biopharmaceutical companies by providing a full package of characterization services. ### Our analytical services for protein characterization ## Structural protein characterization [Amino Acid Sequencing](https://filab.fr/en/our-services/our-analysis-services/chemical-analysis-laboratory/analysis-amino-acids.md) Post-Translational Modifications (PTMs) Carbohydrate Structure (Glycosylation): [Analysis of N-glycan](https://filab.fr/en/sectors-of-activity/biopharmaceutical/n-glycans-analysis.md) and O-glycan profiles (Glycoprofiling) Terminal Amino Acid Analysis [Disulfide Bridges](https://filab.fr/en/sectors-of-activity/biopharmaceutical/disulfide-bridge-analysis.md) services ## Physicochemical Properties We determine the physical and chemical properties using state-of-the-art methods **Molecular Weight:** intact mass measurement by High-Resolution Mass Spectrometry ([HRMS](https://filab.fr/en/our-technical-resources/high-resolution-mass-spectrometry-hrms-analysis.md) - [Orbitrap](https://filab.fr/en/our-technical-resources/lc-orbitrap-analysis.md)/[QTOF](https://filab.fr/en/our-technical-resources/laboratory-for-lc-qtof-analysis.md)) **Isoform Patterns:** analysis of charge variants by Capillary Isoelectric Focusing (cIEF) or Ion Exchange Chromatography (IEX). **Spectroscopic Profiles**: UV-Vis absorption, [Circular Dichroism (CD)](https://filab.fr/en/sectors-of-activity/biopharmaceutical/measurement-circular-dichroism-cd.md), and [FTIR](https://filab.fr/en/our-technical-resources/laboratory-analysis-ftir-spectroscopy.md) for secondary structure assessment **Aggregation & Purity:** detection of aggregates and fragments via [SEC-MALS](https://filab.fr/en/our-technical-resources/laboratory-analysis-gpc-sec.md) (Size Exclusion Chromatography). ### Why is ICH Q6B Characterization critical for Biosimilars? For biosimilar developers, the goal is to demonstrate "biosimilarity" to the reference product. This requires a **head-to-head comparison** showing that the physicochemical and structural attributes are highly similar. **The FILAB Advantage:** We perform comparative studies (Biosimilar vs. Reference) to highlight ensuring that any minor difference in micro-heterogeneity is characterized and justified. ### Why choose FILAB ? - **Dual competence:** Chemistry / Materials - **Analytical facility:** A 5200 m² laboratory equipped with the latest UPLC-MS/MS (Orbitrap, QTOF), cIEF, and SEC-MALS technologies. - **Regulatory expertise**: Our protocols are strictly aligned with ICH Q6B, USP, and Ph. Eur. monographs. - **Agility:** Whether for early-stage R&D characterization or full GMP validation for market release, we adapt to your timeline. - **Problem solving**: We don't just report data; we interpret complex structural behaviors to help you optimize your manufacturing process. ## Our FAQ At what stage should I perform ICH Q6B characterization? Full characterization is typically required for IND (Investigational New Drug) and BLA (Biologics License Application) filings. However, performing structural analysis (like peptide mapping) early in process development prevents costly surprises later regarding stability or immunogenicity. Can you analyze glycosylation profiles? Yes. Glycosylation is a critical quality attribute (CQA) affecting efficacy and safety. We perform N-glycan release and labeling followed by FLD/MS analysis to determine the glycan structures (G0, G1, G2, etc.) and sialylation levels. What is the difference between "Release Testing" and "Characterization"? Release testing involves a limited set of validated tests to confirm batch quality (purity, potency, safety). Characterization is a deeper, one-time (or periodic) comprehensive study to fully understand the molecule's structure and behavior, as described in ICH Q6B. Do you handle complex fusion proteins or ADCs? Absolutely. Our expertise extends beyond standard mAbs to complex modalities like Fc-fusion proteins, bispecifics, and Antibody-Drug Conjugates (ADCs), where linking chemistry adds another layer of complexity. How to get a quote with FILAB? To get a quote, you can contact our team via our [contact form](https://filab.fr/en/contact-form.md), by phone, or by email. Simply send us your requirements (material type, desired analysis, specific standards, urgency, number of samples, etc.). We will then send you a personalized technical and price proposal within **24 to 48 hours**. What is the typical turnaround time for analysis? Turnaround times vary depending on the nature of the analysis and the complexity of the project. However, FILAB is committed to providing fast results tailored to your industrial constraints and urgent needs.