replacing acid-heat precipitation with sodium dodecyl sulphate polyacrylamide gel electrophoresis improves detecting bence-jones proteinuria

background: detecting bence-jones protein in urine is essential for determining plasma cell dyscrasia and multiple myeloma. conventionally, acid-heat precipitation assay is used for detecting bence-jones protein in most medical laboratories; however, because of the low accuracy of this test, other more sensitive tests like urine electrophoresis are recommended.  materials and methods: in this study, the presence of bence-jones protein in the urine of patients suspected to monoclonal gammopathies were compared using acid-heat precipitation, capillary immunoelectrophoresis and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. moreover, the subsets of light chain (κ & λ) in capillary immunoelectrophoresis were determined. results: our data showed high false negative results (77.7%) using acid-heat precipitation assay in comparison with polyacrylamide gel and capillary immunoelectrophoresis (0%). conclusion: collectively, in spite of advantages like easy performance and low cost, acid-heat precipitation assay is not reliable for determining bence-jones proteinuria in medical laboratories due to its low sensitivity. therefore, it is recommended to be replaced with more sensitive assays like electrophoresis. k e y w o r ds: bence-jones protein, monoclonal gammopathies, capillary immuno-electrophoresis, sodium dodecyl sulphate-polyacrylamide gel electrophoresis