[Significance, sources of error and limits of protein diagnosis in urine. I. Diagnostic methods].

Determination of proteins in the urine requires standardized collection and storage of urine. To quantify total protein and to separate single proteins electrophoretically unconcentrated urine should be used. Protein dye-binding methods, beta 2-microglobulin essay and polyacrylamide gel techniques can be recommended for routine urinalysis. However, the analytical limits and pitfalls of the methods must be considered. The application of the selectivity concept of proteinuria is restricted to patients with nephrotic syndrome.