Jorjani Biomedicine Journal

Background and Objective: Extinction coefficient is the unique value to each protein and can evaluate the type and purity of recombinant protein produced in laboratories and factories producing recombinant proteins. In this study, a simple method for calculating the extinction coefficient of recombinant protein Granulocyte-Colony Stimulating Factor (G-CSF) is presented.

Methods: G-CSF with concentration of 0.5 mg/ml was prepared from Arya Tina Gene. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) method was used to check the purity of the protein, then serial dilutions of 1/2 to 1/64 of the protein were prepared and using UV-VIS spectroscopy the optical density was measured.

Results: Electrophoresis result as a single band of 18 kDa was observed. The results of UV-VIS spectroscopy of serial dilution were plotted as a distinct spectrograms and these were used to plot linear regression curve of the standard concentration of G-CSF.

Conclusion: The results of this study shows the extinction coefficient equal to 0.81 M^-1 cm^-1 for recombinant G-CSF that was accordant with the number reports by international producers of G-CSF and suggests the correct method is used to calculate the physicochemical parameter.