WHAT IS PROTEIN ELECTROPHORESIS (URINE) TEST?
Normally the urine is free of protein or contains only trace amounts of albumin and globulin because the glomeruli prevent the passage of proteins from the plasma to the glomerular filtrate. Protein electrophoresis is a quantitative measurement of proteins, which under the influence of an electrical field, at a pH of 8.6, separate by charge, size, and shape. The separation produces homogeneous bands that are plotted on treated paper. Protein electrophoresis detects the presence of free light chains and other proteins associated with myoclonal gammopathies. The normally round and broad curves form a “church spire,” or sharp peak. The immunoelectrophoretic technique is able to demonstrate a large number of components that are identical to the serum electrophoretic patterns. It is used to identify light-chain, Bence Jones, and kappa-, lambda-, and heavy-chain proteins. The test helps detect specific abnormalities by identifying patterns of protein characteristic of different disease states. The meaning of the results of urine electrophoresis is best interpreted when the test is run simultaneously with a serum sample for electrophoresis.