Immunofixation electrophoresis for identification of proteins and specific antibodies.

Immunofixation electrophoresis (IFE) is a technique for the identification of proteins within complex mixtures after separation by either conventional zone electrophoresis or isoelectric focusing. Most commonly antigens (which are often immunoglobulins) are separated by electrophoresis followed by precipitation with specific antibodies in situ. However, immunoglobulins with specific reactivity can be also precipitated with the proper antigens after electrophoresis in reverse or reversed IFE. Because of its great versatility, potentially high sensitivity, ease to perform and customize, and relatively low cost with no requirement for expensive instrumentation, manual IFE remains a valuable tool for both clinical diagnostic testing and research. Any low-viscosity body fluid specimen or, possibly, culture fluid could be tested with IFE if proper antibodies (or antigens in reverse[d] IFE) are available. After pretreatment with chaotropic and/or reducing agents, even high-viscosity specimens might be amenable to testing with IFE.