Da Yu Protein Sciences – Analytical Characterization
Analytical characterization is an essential component of any therapeutic protein program in CMC development. It contributes to forming the analytical control strategy, helps define critical quality attributes and supports comparability testing through commercial launch. Da Yu Protein Sciences has broad experience with a wide range of analytical technologies applied to therapeutic protein candidates. Our current laboratory-based analytical services include:
- Amino Acid Analysis
- Extinction Coefficient Determination
- N-Terminal Sequencing (Edman Degradation)
- Size-Exclusion HPLC with Multi-Angle Laser Light Scattering (SEC-MALLS)
- Protein Mass by MALDI or LC-MS
Extinction Coefficient Determination – Protein concentration is generally determined by UV absorbance spectroscopy at 280 nm using the Beer-Lambert Law (A280 = εcl). Since the pathlength (l) is generally kept constant at 1 cm, the 
reliability of the protein concentration is dependent on ε, the extinction coefficient. The determination of the extinction coefficient should be both accurate and precise because the resulting protein concentration will likely be used for critical applications such as potency testing and patient dosing. The extinction coefficient’s precision is addressed by performing determinations on multiple days. The accuracy, however, is dependent on the technique used to establish the protein concentration of the reference standard used in the extinction coefficient determination. Acceptable analytical techniques for this purpose include quantitative amino acid analysis, UV difference spectroscopy and reversed-phase HPLC using an internationally recognized protein standard.
For more information on our analytical laboratory services please Contact Us.