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Updated: Aug 2, 2026

High-throughput Fluorometric Measurement of Potential Soil Extracellular Enzyme Activities
Published on: November 15, 2013
More on effects of storage time and temperature on urinary enzymes: a 1-year study
E Matteucci1, L Pellegrini, C Uncini-Manganelli
1Postgraduate Medical School of Clinical Pathology, University of Pisa, Italy.
Abstract:
Results of our conclusive study on urinary enzyme stability during sample storage are reported. We measured alanine aminopeptidase (AAP) and N-acetyl-beta-D-glucosaminidase (NAG) in morning urines from 9 healthy normal subjects immediately after collection and throughout a 1-year storage at -70 and -20 degrees C. AAP proved to be quite stable at -70 degrees C (99.2% of the basal value at the end of the year). NAG is partially preserved (84.1% of the basal value) at -70 degrees C, but significantly decreased (50.4%) at -20 degrees C.
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