Standard Article


  1. Stanley S Levinson

Published Online: 15 SEP 2009

DOI: 10.1002/9780470015902.a0001136.pub2



How to Cite

Levinson, S. S. 2009. Immunoelectrophoresis. eLS. .

Author Information

  1. University of Louisville, Louisville, Kentucky, USA

Publication History

  1. Published Online: 15 SEP 2009


Immunoelectrophoresis is a two-stage process. Electrophoresis is conducted in the first stage and immunoprecipitation using antibodies against specific proteins in the second stage without removing the proteins from the separation media (usually agarose). Four types of immunoelectrophoresis (IEP) have been used: electroimmunoassay (EIA also called ‘rocket’ or ‘Laurell rocket’), classical IEP, immunofixation electrophoresis (IFE) and immunoprecipitation of proteins after capillary electrophoresis. The procedure used in most medical laboratories is IFE where the proteins are immunoprecipitated on the gel in a pattern that is similar to their location on routine agarose gel electrophoresis. This type of immunoelectrophoreisis is easier to interpret and more sensitive than the IEP that it replaced. The principles underlying each method and the strengths and weaknesses of each is described. Example of IEP and IFE for identifying monoclonal proteins in serum and urine and the relationship of the proteins to disease is discussed.

Key concepts

  • Immunoelectrophoresis differs from blotting techniques because with IE the entire procedure is conducted in an agarose gel and blotting is not necessary.

  • These techniques are based on the concept that near equivalency an antigen–antibody complex will precipitate and become trapped in the gel.

  • Immunofixation electrophoresis (IFE) is preferred over immunoelectrophoresis because of its greater sensitivity and simpler interpretation characteristics.

  • Immunofixation electrophoresis is largely used in medical or clinical laboratories for identifying abnormal monoclonal immunoglobulins associated with diseases of lymphocytes such as multiple myeloma.

  • The abnormal protein bands identified on IFE line up with bands seen on routine agarose electrophoresis making interpretation simpler.

  • Proteins in large concentration can cause prozoning on IFE causing more difficulty in interpretation.

  • IFE is widely used in medical laboratories for identifying monoclonal free light chains in urine, called Bence Jones proteins.

  • IFE can also be used for identifying oligoclonal banding in cerebrospinal fluid.


  • immunoelectrophoresis;
  • immunofixation electrophoresis;
  • electro immunoassay;
  • agarose gel electrophoresis