Analysis of proteins incidence in urine belongs to basic examination methods in nephrologic practice. Quantification of proteinuria itself provides useful but only limited information.We describe how to obtain more exact informations (facts) for differencial diagnostics and determination of proteinuria types. The proposed procedure is based on qualitative and quantitative evaluation of urine proteins after their fractionation on SDS-PAGE followed by a digitalization of stained electrophoreogram (gel) by a simple scanner and by computer data processing resulting in graphical output. The electrophoretic separation (10 % polyacrylamid gel) of urine samples is very convenient because it brings complete information about qualitative and quantitative protein composition of urine. Evaluation of tubular proteins is of first importance because their contribute significantly to tubular injuries. Proposed approach is very effective for a differential diagnostics of nephropathy with injured glomerules and tubules.

        Key words: proteinuria, SDS-PAGE, UN-SCSN-IT, nephropathy.