To detect clonal light chains. Useful in characterizing the species of protein in cases of proteinuria. Techniques can identify intact monoclonal protein and free light chains (Bence Jones protein). Of value in the study of monoclonal gammopathies and lymphoproliferative diseases, including lymphoma, multiple myeloma and Waldenstrom’s macroglobulinemia. Urine immunofixation is essential in amyloidosis or if a monoclonal band is present on urine protein electrophoresis.