Isoelectric point (pI) determination: characterizing the charge of your proteins
The Isoelectric Point (pI) is a fundamental physicochemical parameter in the development of therapeutic proteins (monoclonal antibodies, enzymes, hormones).
It corresponds to the pH at which the protein's net charge is zero.
Controlling the pI is essential to ensure the stability, solubility, and biological activity of your biomolecules.
Any variation in the pI may reveal post-translational modifications (deamidation, sialylation, C-terminal lysine clipping) that directly affect the homogeneity and safety of your product.
The FILAB laboratory supports you in the precise measurement of pI and the study of charge heterogeneity, in accordance with the requirements of the ICH Q6B.
guidelineOur isoelectric point analysis services
Isoelectric Point
Experimental pI measurement : precise determination of the isoelectric point value of the protein of interest.
Charge heterogeneity profiling : identification and quantification of acidic and basic variants (charge variants).
Stability and degradation studies : monitoring changes in pI under stress conditions (temperature, pH, light).
Comparability studies: assessment of biosimilarity between a reference product and a biosimilar candidate.
Our Technical Resources
Our other biopharmaceutical analysis services
Analysis and localization of disulfide bonds
Protein analysis according to the following methods: BCA method, Lowry method, CBQCA method, Bradford method
Why choose FILAB?
- Multidisciplinary expertise: a team of PhD scientists and engineers specializing in analytical chemistry and biochemistry.
- Dual expertise in chemistry / materials
- ISO 17025 accreditation by COFRAC
- State-of-the-art analytical facility spanning 5,200 m²
- GMP environment
