Bence Jones protein detection: a rapid immunoblotting technique for routine use on unconcentrated urine.

A new immunoblotting method is described for the detection of Bence Jones proteinuria by the routine laboratory. Unconcentrated urine specimens are subjected to electrophoresis on agarose gels. Separated proteins are transferred to a nitrocellulose membrane and the immunoglobulins located and identified by horseradish-peroxidase double-antibody staining. The new method has been compared with that used routinely, and an improved rate of detection of both Bence Jones protein and intact urinary monoclonal immunoglobulin has been obtained. Among urine specimens received for routine testing for Bence Jones protein from 83 patients, 64 monoclonal components were found by the new technique compared with 45 by the method used routinely. Other advantages of the new procedure include: no need to concentrate urine specimens before electrophoresis; unlike immunofixation, the proteins may be detected successfully over a wide concentration range without using several specimen or antibody dilutions; and interpretation is easier.