Improving recovery of recombinant hepatitis B virus surface antigen by ion-exchange chromatography whit changing salt concentration in buffer

Ion exchange chromatography known as a method used for protein purification. In this research ionic strength of buffer was altered to find out the best condition process. As Expected that the buffer conductivity affects the ionic bond between desired protein and adsorbent it may play an important role in increasing recovery of [HBsAg]. The experiments designed by using taguchi method. Optimum buffer condition for equilibration, washing and elution was chosen 3.5, 11 and 50 ms/cm respectively. We did IEC on DEAE by these values and raise the efficiency up to 82%. Compare to the previous process condition. We could increase the efficiency of this step from 40% to 82% by altering the ionic strength buffers. We could explain that doing equilibration with a buffer with higher ionic strength may cause the bond make weaker and also washing loosen the bond so by increasing the ionic strength of elution [HBsAg] released and other negatively charged impurities remained attached to the media.