[Methodological aspects of urinary enzymology].

Collection and storage of the sample exert significant influences on the results of urinary enzyme determinations. Enzymes with sufficient stability during urine collection and consecutive in vitro storage are probably best suited for diagnostic purposes. Sample preparation, e.g. by gel filtration of the urine should be performed to remove quantitatively interferences. Optimized methods for some urinary enzymes are now available offering a basis for standardization. Analytical results should be verified by the use of self-prepared or commercially available quality control materials. The modern clinical chemical technology permits the determination of enzyme activities in urine with a quality standard comparable to that in other body fluids. New approaches are the development of a dipstick test for beta-N-acetylglucosaminidase and the use of immunological techniques for the measurement of enzyme concentrations in urine.