Immunoelectrophoresis is a general name for a number of biochemical methods for separation and characterization of proteins based on electrophoresis and reaction with antibodies. All variants of immunoelectrophoresis require immunoglobulins, also known as antibodies, reacting with the proteins to be separated or characterized. The methods were developed and used extensively during the second half of the 20th century. In somewhat chronological order: Immunoelectrophoretic analysis, crossed immunoelectrophoresis, rocket-immunoelectrophoresis, fused rocket immunoelectrophoresis ad modum Svendsen and Harboe, affinity immunoelectrophoresis ad modum Bøg-Hansen.
Crossed immunoelectrophoresis of 2 microlitres of normal human serum. The electrophoresis was performed in thin layers of agarose; the pictured gel is about 7x7 cm. The lower part is the first dimension gel without antibodies, where the serum was applied into the slot at the lower left. The upper part is the second dimension gel with Dako antibodies against human serum proteins. More than 50 major serum proteins can be named.
Fused rocket immunoelectrophoresis of an affinity chromatographic separation of human serum proteins on con A. A 15 microlitre sample from each fraction was applied (starting from left) and allowed to diffuse about one hour, then electrophoresis was performed overnight. Peak "a" was not retained, while peak "b" was retained and eluted with methyl-mannose. The arrow indicates some slightly retained proteins.
Plasmodium Glutamate dehydrogenase (pGluDH) separated by Counterimmunoelectrophoresis
An antibody (Ab) is the secreted form of a B cell receptor; the term immunoglobulin (Ig) can refer to either the membrane-bound form or the secreted form of the B cell receptor, but they are, broadly speaking, the same protein, and so the terms are often treated as synonymous. Antibodies are large, Y-shaped proteins belonging to the immunoglobulin superfamily which are used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that cause disease. Antibodies can recognize virtually any size antigen with diverse chemical compositions from molecules. Each antibody recognizes one or more specific antigens. Antigen literally means "antibody generator", as it is the presence of an antigen that drives the formation of an antigen-specific antibody. Each tip of the "Y" of an antibody contains a paratope that specifically binds to one particular epitope on an antigen, allowing the two molecules to bind together with precision. Using this mechanism, antibodies can effectively "tag" a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly.
Angel of the West (2008) by Julian Voss-Andreae is a sculpture based on the antibody structure published by E. Padlan. Created for the Florida campus of the Scripps Research Institute, the antibody is placed into a ring referencing Leonardo da Vinci's Vitruvian Man thus highlighting the similarity of the antibody and the human body.
Michael Heidelberger
Immunofluorescence image of the eukaryotic cytoskeleton. Microtubules as shown in green, are marked by an antibody conjugated to a green fluorescing molecule, FITC.
