Detection of monoclonal proteins by capillary electrophoresis using a zwitterion in the running buffer.
Some cases have been reported in which a small monoclonal protein (M-protein) cannot be detected by conventional cellulose acetate membrane electrophoresis (CAE) or capillary zone electrophoresis (CZE) using a short fused-silica capillary. This is probably because these methods do not have the necessary sensitivity or resolution. To overcome this problem, we improved the CZE system by using a longer capillary and adding a zwitterion to the running buffer (pH 10.0). A comparison of CZE and CAE demonstrated that with the exception of alpha(1)- and alpha(2)-globulin, the correlation was satisfactory in serum samples from 34 patients with M-proteins which had been detected by immunoelectrophoresis. In addition, a comparison of CZE electropherograms with those from CAE showed that small M-proteins that went undetected by CAE could be detected by CZE in four patients whose diseases included epipharyngeal carcinoma, solitary plasmacytoma, Crow-Fukase syndrome and macroglobulinemia. The improved resolution produced by a longer capillary may be effective for the detection of small M-proteins.
Miura
T
T
Department of Clinical Laboratory and Medicine. Tohoku University School of Medicine, 1-1 Seiryou-machi, Aoba-ku, 980-8574, Sendai, Japan. tm30130@mail.cc.tohoku.ac.jp
Funato
T
T
Yabuki
S
S
Sasaki
T
T
Kaku
M
M
D000911:Antibodies, Monoclonal / Q000032:analysis*; D002021:Buffers; D019075:Electrophoresis, Capillary; D004588:Electrophoresis, Cellulose Acetate; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007136:Immunoglobulins / Q000032:analysis; D007202:Indicators and Reagents; D007477:Ions
D000911:Antibodies, Monoclonal; D002021:Buffers; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D007202:Indicators and Reagents; D007477:Ions