immunofixationin

Immunofixation is a laboratory technique used to identify and characterize specific proteins in a biological sample. It is a sensitive method that combines electrophoresis with immunodiffusion. In essence, it is a qualitative assay, meaning it is used to determine the presence or absence of specific proteins rather than their exact quantity.

The process begins with electrophoresis, where proteins in a sample are separated based on their charge and size as they migrate through a gel medium. After separation, an antiserum containing antibodies specific to the proteins of interest is applied directly over the electrophoretic bands. If the target protein is present, it will react with its specific antibody, forming an antigen-antibody precipitate. These precipitates are insoluble and remain in the gel.

Following incubation, the gel is washed to remove any unbound proteins and antibodies. The remaining precipitates are then visualized, typically by staining. The location and pattern of these stained precipitates allow for the identification of specific proteins. This technique is particularly valuable in the diagnosis and monitoring of monoclonal gammopathies, such as multiple myeloma, where abnormal amounts of a single type of immunoglobulin (antibody) are produced. It can also be used to detect other abnormal proteins in various biological fluids like urine and cerebrospinal fluid. Immunofixation provides a high degree of specificity and sensitivity for protein identification.