What is the most important clinical application of electrophoresis?

• A. Oligoclonal banding/Monoclonal gammopathy
• B. Separation of enzymes
• C. pI determination
• D. Gel filtration

Answer: (A)

Electrophoresis is most powerful in clinical practice for revealing abnormal immunoglobulins produced by a clone of plasma cells. When a patient has a monoclonal gammopathy, the serum pattern shows a sharp, well-defined band in the gamma region, called an M-spike, which points to disorders like multiple myeloma, MGUS, or Waldenström’s macroglobulinemia. In CSF, the appearance of oligoclonal bands similarly indicates inflammatory or demyelinating processes such as multiple sclerosis. This ability to detect and characterize clonal immunoglobulin production is why this application is considered the most important clinical use of electrophoresis. Other uses—such as separating enzymes, determining the isoelectric point, or gel filtration—are less central to routine clinical diagnostics.