Immunoaffinity purification of human haptoglobin using monoclonal antibodies

Two monoclonal antibodies, coupled to Sepharose 4B, were used for rapid isolation of the human haptoglobin in a single chromatographic step. The purity of haptoglobin was judged by SDS polyacrylamide gel electrophoresis, immunoblotting, immunoelectrophoresis and size exclusion high performance liquid chromatography. Moreover, the preparation showed ability to form active complexes with hemoglobin, Concanavalin A and specific antibody. Polyclonal goat antiserum produced with the obtained haptoglobin preparation formed one precipitin line with whole human serum. On the other hand, monoclonal antibodies can be purified by means of haptoglobin coupled to matrix.