Uric Acid, Urine

Additional Information:

UFHPL Test #: 20502

CPT Code(s):

84560

Collection Procedure:

Serum gel tubes should be centrifuged within 2 hours of collection.

Specimen Requirements:

Type: Timed, 24-hour urine

Sample Volume: 1 mL

Stability (collection to time of analysis/testing): To prevent urate precipitation in urine specimens, after specimen collection, add a sufficient volume of sodium hydroxide solution to bring the pH between 8 and 9.

  • Ambient: 3 days

Use:

-

Methodology:

Uric acid can be determined by direct measurement, by measurement of oxygen consumed or by measurement of hydrogen peroxide produced by the uricase reaction. Several methods utilize coupled enzyme reactions to detect the hydrogen peroxide produced by the uricase reaction. Fossati (et al) proposed a method that utilized the well-established Trinder reaction to measure the hydrogen peroxide produced and a substituted phenol to enhance sensitivity. This Uric Acid procedure is a modifcation of the Fossati method. Uric acid is converted by uricase to allantoin and hydrogen peroxide. Hydrogen peroxide reacts with 4-aminoantipyrine (4-AAP) in the presence of N,N-bis(4-sulfobutyl)-3,5-dimethylaniline, disodium salt (MADB) to produce a chromophore which is read bichromatically at 660/800 nm. The amount of dye formed is proportional to the uric acid concentration in the sample.

Reported:

Within 24 hours

Reference Values:

  • Female: 250 – 750 mg/24 hours
  • Male: 250 – 800 mg/24 hours

Performed:

Monday - Friday

Interpretation Data:

-