Urine protein analysis by capillary electrophoresis.

Increased concentration of proteins in urine as well as abnormal patterns are seen in many disorders such as various renal disorders and light chain disease. At the wavelength of 214 nm used for detection of the peptide bond, numerous compounds interfere in the analysis of urinary proteins. We show that either adsorptive filtration with a wash step or cold ethanol precipitation are two methods which can eliminate many of the interferences. The wash step is rapid, greatly reduces the interfering substances, and decreases the effect of sample matrix. Both of these methods yield results comparable to the traditional agarose method. Capillary electrophoresis (CE) is faster and more cost-effective than agarose electrophoresis.