[Separation strategy of affinity chromatography for mixed antibodies]

A mammary gland bioreactor can efficiently express human recombinant monoclonal antibody. However, the target products are similar to the bovine antibody in the raw emulsion material in properties and structures. Thus it is difficult to achieve effective separation of the target products. In this work, the species differences between bovine antibody and recombinant human antibody were analyzed and a new separation strategy was raised based on it. We employed two kinds of affinity chromatography to separate these two antibodies from each other and studied the effect of elution mode upon separation. The results demonstrated that Protein A affinity chromatography could get hybrid antibodies using gradient elution mode, but hardly separate the recombinant human antibody and bovine antibody from each other. In contrast, the combination of Protein A affinity chromatography and displacement chromatography could separate the hybrid antibodies effectively and finally give recombinant human IgG (rHGG) product with the purity of 95% and the yield of more than 95%. Immuno-affinity chromatography could also effectively purify recombinant monoclonal antibodies and owned better generality, which could be used in purification of recombinant antibody expressed by any animal mammary gland. -