Rapid colorimetric assay of urinary β‐galactosidase and N‐acetyl‐β‐glucosaminidase with cobas mire auto‐analyzer

摘要

A rapid and simple colorimetric method for the assay of urinary β‐galactosidase (GAL) and ‐acetyl‐β‐ ‐glucosaminidase (NAG) using 4‐nitrophenyl‐glycosides as the substrates and a Cobas Mire Auto‐analyzer is described. Optimal conditions for this method including substrate concentration, ionic strength, pH and incubation time were characterized. Endogenous substances in urine did not interfere with the assays. Incubation time could be shortened to 10 minutes. A small volume of an alkaline buffer to terminate the enzyme reaction achieved better sensitivity and accuracy. Buffer‐substrate solutions were stable for at least one week at 4°C. Normal values of the two urinary enzymes are also reported. J. Clin. Lab. Anal. 13:95–98, 1999. © 1999 Wiley‐Liss, Inc.