Clinical Lab Handbook

Timed urine collection, preferably a 24 hour urine collection, with no preservative.

Collect specimens using standard laboratory procedures. Refer to the Laboratory User's Guide for timed urine collection procedures.

Specimen should be room temperature during collection and until analysis.

Collection start and end times should be clearly marked on specimen container.

Colorimetric, Uricase

The VITROS URIC Slide is a multilayered, analytical element coated on a polyester support. The method is similar to those described by Kageyama 2 and Trivedi et al. A drop of patient sample is deposited on the slide and is evenly distributed by the spreading layer to the underlying layers. Uric acid from the sample migrates to the reagent layer, where it is oxidized in the presence of uricase to form allantoin and hydrogen peroxide. Hydrogen peroxide oxidzes a leuco dye in the presence of peroxidase to generate a colored dye. The reflection density of the dye is measured by reflectance spectrophotometry.

Uric acid is the end product of purine metabolism. Elevations of uric acid occur in renal failure, prerenal azotemia, gout, lead poisoning, excessive cell destruction (e.g., following chemotherapy), hemolytic anemia, and congestive heart failure and after myocardial infarction. Uric acid is also increased in some endocrine disorders, acidosis, toxemia of pregnancy, hereditary gout, and glycogen storage disease type I. A low uric acid concentration may be found following treatment by some drugs (e.g., low-dose aspirin), with low dietary intake of purines, in the presence of renal tubular defects, and in xanthinuria.

Monday through Sunday

81050-Urine timed measurement

84560-Uric acid