Extinction Coefficient Determination Service

The protein concentration is an important parameter affecting the efficacy of pharmaceutical products. Therefore, it is essential and necessary to determine the concentration of a protein solution during drug development. There are several methods for protein concentration determination, such as include UV absorption, the Braford assay, the bicinchoninic acid (BCA) assay, and so forth. To determine the protein concentration UV absorption, absorption in the UV region of the spectrum will be measure, and the concentration will be calculated according to the Beer-Lambert law, where extinction coefficient and path length are constant. Extinction coefficient, a measure of how strongly a substance absorbs light at a specific wavelength, is the intrinsic property of a protein depending on its composition and structure. Hence, to precisely determine protein concentration, it is fundamental to accurately determine extinction coefficient. Creative Proteomics offers reliable service to help you determine the extinction coefficient accurately, in accordance with the ICH Q6B Guidelines.

Extinction Coefficient Determination Service

We Can Provide but Not Limited to:

  • Extinction coefficient determination
  • Protein solution concentration

Technology Platform of Extinction Coefficient Determination Service

The common approach to determine extinction coefficient is based on theoretical prediction from the amino acid sequence, but the spectral properties of a protein can be influenced by the folding state. Another approach to determine extinction coefficient take advantage of the photometric determination coupled with a measurement of absolute protein concentration, including total nitrogen determination, quantitative amino acid analysis, or dry weight determination. Here, a sedimentation velocity analytical ultracentrifugation (SV-AUC) based method equipped with absorbance and Rayleigh interference optics will be adopted to conveniently determine extinction coefficient.

Our extinction coefficient determination service mainly contains 3 steps. 1)  Samples will be purified to minimize the effects of interfering buffer excipients. 2) Samples will be diluted, and the experimental AUC will be conducted with ProteomeLab XL-I equipped with interference and absorbance OPTICS. 3). AUC data will be analyzed.

One of advantages of SU-AUC based method is no limitations regarding column stability, etc. According to your special requirements, optimized techniques will be employed to accurately determine the extinction coefficient.

Extinction Coefficient Determination Service

Advantages of Extinction Coefficient Determination Service:

  • Rich experience in protein analysis.
  • High sensitivity and accuracy to detect proteins with different post-translational modifications.
  • Batch-to-batch consistency.
  • Rapid Turnaround Time: 5-7 days to provide comprehensive report.
  • Customized service: according to you sample type and sample size, optimized protocols will be deployed.

Creative Proteomics's experienced scientists will provide you with a high-sensitivity and accurate extinction coefficient determination of biopharmaceutical products. Our service will be optimized to reach your special requirements. Clear and concise written reports including protocols and customized services will be offered during drug development.

Want to learn more about Extinction Coefficient Determination service? Please contact us.


  • Hoffmann A., Grassl K., Gommert J., et al. Precise determination of protein extinction coefficients under native and denaturing conditions using SV-AUC. European Biophysics Journal, (2018) 47:761–768.
  • Hilario E.C., Stern A., Wang C.H., et al. An improved method of predicting extinction coefficients for the determination of protein concentration. PDA Journal of Pharmaceutical Science and Technology, March 2017, 71 (2) 127-135.

*For Research Use Only. Not for use in the treatment or diagnosis of disease.

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