IMG_4854 Calculate concentration with confidence

What’s a good way to demonstrate consistency and comparability between your product batches? Ask us to find out the protein concentration through the determination of the extinction coefficient of your sample.

We find the extinction coefficient by employing two methods: amino acid analysis and UV light absorption at 280 nm. This is in line with ICH Q6B, which recommends determining the coefficient (sometimes referred to as molar absorptivity) by a combination of the two.

Why do we use UV absorption at 280 nm? Because in complex solutions, proteins are not the only molecules that absorb UV light. Other compounds can skew the results, but their interference is minimized when we measure absorbances at this UV level.

Once we’ve found the extinction coefficient, we can combine it with other knowledge about your protein, such as amino acid composition, to give you complete peace of mind about the concentration of protein in your samples.

In order to determine the mass extinction coefficient, amino acid analysis is combined with MALDI-TOF to determine the intact mass of the protein.

Your contact for Extinction Coefficient Determination at Protagen Protein Services GmbH


Dr. Marcus Mreyen

Director Business Development
Our business development team will be happy to assist you with your project.

Phone: +49 (0) 231 9742-6100