Purification of Myeloma Proteins by Iso-electric Focusing

Publisher Summary This chapter discusses the purification of myeloma proteins by isoelectric focusing. In this method, the serum and in one case the pleural effusion of patients suffering from multiple myeloma were separated by means of chromatography on DEAE-cellulose columns. The elution of the proteins was at first carried out with 0.02 M phosphate buffer pH 8.0, followed by a linear gradient of 0.02 to 0.3 M phosphate buffer pH 8.0. The fraction containing the myeloma protein was concentrated in Visking-tubes by negative pressure and then dialyzed against a solution of 1 to 2% glycine. The electro-focusing experiments were carried out according to methods described by Svensson, and Vesterberg and Svensson. The DEAE fractions of five patients suffering from γG myeloma were examined by iso-electric focusing. A sharp peak is seen. The immunoelectrophoretical analysis of the DEAE fraction shows a splitting of the γG line, which is characteristic for multiple myeloma. The analysis of the fraction that is purified by iso-electric focusing demonstrates that the splitting of the γG line disappears