Immunofixation following electrophoresis or isoelectric focusing for identification and phenotyping of proteins

Immunofixation following electrophoresis or isoelectric focusing has proven to be a powerful tool for the phenotyping of plasma proteins, the identification of proteins such as M-components and the study of conversion or breakdown products of proteins such as C3. One of the major advantages is the ability to compare, side by side, the mobilities of relatively low-concentration proteins. The technique is relatively simple, can be used with most types of gels and can be enhanced when necessary by the use of enzyme- or radiolabeled antibodies. The cost is competitive with other immunochemical procedures which are more tedious but which give less information.