Optimized preparation of urine samples for two-dimensional electrophoresis and initial application to patient samples

Objectives We optimized of the preparation of urinary samples to obtain a comprehensive map of urinary proteins of healthy subjects and then compared this map with the ones obtained with patient samples to show that the pattern was specific of their kidney disease. Design and methods The urinary protein excretion patterns of 49 healthy men and 4 patients with renal disease were obtained by 2D electrophoresis. Silver nitrate stained protein spots were identified by mass spectrometry. Results Reproductive 2D gels identified 5 classes of proteins systematically found in healthy subjects, irrespective of age. The proteins evidenced included serum albumin and its specific proteolytic products, Tamm-Horsfall, transferrin, zinc-α2-glycoprotein, α1-microglobulin, haptoglobin, and Ig light chains. Conclusions This study of a large panel of healthy individual showed that 2D urinary pattern was constant over time and reveal for the first time the relative abundance of albumin fragments in healthy subjects’ urine. The profiles of the 4 patients, were specific of their renal disease.