Immunofixation. Ill. Application to the Study of Monoclonal Proteins

We have shown how immunofixation can be successfully used to study proteins exhibiting electrophoretic poly-morphism. An analogous situation is seen in the disorders of the immune system that result in the production of variable quantities of homogeneous immunoglobulins. Immunoelectrophoresis has been heavily used-some-times unsuccessfully because of poor resolution-to study these materials. The appearance of a monoclonal immu-noglobulin band is identical in both immunofixation and standard gel electrophoresis, a feature that allows un-ambiguous identification of a protein as to its heavy-chain class and light-chain type. Because antigen and antibody are placed in contact almost immediately after electro-phoresis, interfering diffusion does not occur and even extremely small bands can be demonstrated and charac-terized. AddItIonal Keyphrases: immunoelectrophoresis #{149}elec-trophoresis #{149}immunoglobulins #{149}plasma pro-teins #{149}myeloma #{149} “M ” component #{149}diagnosis and prognosis Many disorders of the immune system result in the production of various amounts of homogeneous im-munoglobulins. Since the advent of microimmuno-electrophoresis and an understanding that the immu-noglobulins occur in five distinct classes, each subdi-vided into two major types by virtue of their heavy- and light-chain components, identification of these proteins by use of monospecific antisera has become widespread. Nowhere has immunoelectrophoresis been used more extensively, in both clinical and research laboratories, than in the study of monoclonal proteins. Although immunoelectrophoresis generally fails to identify a monoclonal protein and may produce ambiguous re-sults, even when the abnormal fraction is in high con-centration, this essentially unimproved test continues to increase in popularity