Proteins and peptides including aromatic amino acid side chains indicate strong UV-light absorption, and each protein has a different UV spectrum. Proteins and peptides absorb UV radiation in proportion to their amino acid content and total concentration. Different proteins can have very different extinction coefficients. Amino acid analysis allows you to measure the protein concentration of products and control the manufacturing process.
Yaohai Bio-Pharma offers a service to estimate and determine the extinction coefficient of your products by amino acids analyzers.
We have been involved in the Protein Structural Characterization of various large molecules, including Recombinant Subunit Vaccines, Nanobodies/VHHs/ Single-domain Antibodies (sdAbs), Antibody Fragments, Hormones/Peptides, Cytokines, Growth Factors (GF), Enzymes, Collagens, etc.
Regulatory Requirements for Extinction Coefficient
As the ICH Q6B guidelines recommend, “In many cases, it will be desirable to determine the extinction coefficient (or molar absorptivity) for the desired product at a particular UV/visible wavelength (e.g., 280 nm). The extinction coefficient is determined using UV/visible spectrophotometry on a solution of the product having a known protein content as determined by techniques such as amino acid compositional analysis, or nitrogen determination, etc. If UV absorption is used to measure protein content, the extinction coefficient for the particular product should be used.”
Analytical Method
| Analysis |
Methods |
| Extinction Coefficient |
Amino Acid Analyzers |
EN
AR
HR
CS
DA
NL
FI
FR
DE
EL
IT
JA
KO
NO
PL
PT
RO
RU
ES
SV
IW
ID
LV
LT
SR
SK
SL
UK
VI
ET
HU
TH
TR
FA
AF
MS
BE
MK
UR
BN
