Abstract
Monoclonal gammopathies are characterized by the abnormal proliferation of a single clone of B lymphocytes, usually a plasma cell, which often results in the excess production of a monoclonal immunoglobulin (M-protein). The M-protein is an important part of the diagnosis and management of patients with monoclonal gammopathies. Protein electrophoresis and immunofixation have provided a simple and effective way to detect, quantitate and identify M-proteins in serum and urine for decades. However, improvements in the treatment of multiple myeloma are now driving the development of more sensitive and specific laboratory tests. In this chapter, we review the different monoclonal gammopathies, discuss the current electrophoretic techniques, and discuss new approaches that are being developed to detect the M-protein.