A comparison of three procedures for the detection of Bence-Jones proteinuria

A traditional electrophoretic procedure for detection of Bence-Jones proteinuria, employing Amido black stain on 200-fold concentrated urine, has been compared to two procedures employing highly sensitive protein stains not requiring prior urine concentration. All three procedures were carried out on 80 random urine samples screened for Bence-Jones proteinuria and 10 samples were provided by patients attending a myeloma clinic. A new procedure employing modified Coomassie brilliant blue stain on unconcentrated urine showed comparable sensitivity to the established procedure (82% versus 88%, respectively) and specificity (77% versus 74%, respectively), when assessed against immunofixation as a reference method. However, the new method is considerably quicker and cheaper. A second method, employing Gold stain, showed enhanced sensitivity (94% versus 88% for Amido black) but lower specificity (62% versus 74% for Amido black). However, this method is labour intensive and relatively expensive. Our data suggest that the procedure employing modified Coomassie brilliant blue may be a suitable alternative to the traditional procedure commonly used in many clinical laboratories.