Comparison of Adsorbent with Varying Spacer Arm Length and Ligand Density for the Purification of Recombinant Hepatitis B Virus Surface Antigen

Novel hydrophobic adsorbents were synthesized by immobilizing butyl derivative onto the highly cross-linked agarose beads manufactured in China, which are used as matrix. The effects of the spacer arm length (3C, 8C, and 10C) and ligand density (from 13 to 45 μmol/mL) on the hydrophobicity were investigated using purified Hepatitis B surface antigen (HBsAg) expressed by CHO cell lines. Also, considering the effects of salt concentration and pH on HBsAg recovery and purification factor, orthogonal experiment design method was used to evaluate the adsorbents. The results showed the butyl-S adsorbent with the spacer arm length of 8C and the ligand density of 22 μmol/mL gel showed the best performance for the separation of HBsAg. Approximately 100% HBsAg recovery and 60 as purification fold were achieved by this media under the operating conditions of pH 7.0 and 9% salt concentration.