Abstract
Immunofixation in agarose gel has been compared with agarose electrophoresis for the detection of Bence Jones protein in urine. The technique has a sensitivity between five and 10 times greater than electrophoresis and allows the identification of multiple Bence Jones proteins and Bence Jones proteins with fast mobility in the presence of other urinary proteins. In four out of 12 patients studied, Bence Jones protein was undetectable by electrophoresis of 300 times concentrated urine but was clearly identified by immunofixation.