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Test Code CRT24 Creatinine, 24 Hour, Urine


Specimen Required


Only orderable as part of a profile. For more information see:

-NMH24 / N-Methylhistamine, 24 Hour, Urine

-RB24 / Retinol-Binding Protein, 24 Hour, Urine

-A124 / Alpha-1-Microglobulin, 24 Hour, Urine


Useful For

Urinary creatinine, in conjunction with serum creatinine, is used to calculate the creatinine clearance, a measure of renal function

 

Normalizing urinary analytes to account for the variation in urinary concentration

Method Name

Only orderable as part of a profile. For more information see:

-NMH24 / N-Methylhistamine, 24 Hour, Urine

-RB24 / Retinol-Binding Protein, 24 Hour, Urine

-A124 / Alpha-1-Microglobulin, 24 Hour, Urine

 

Enzymatic Colorimetric Assay

Reporting Name

Creatinine, 24 HR, U

Specimen Type

Urine

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 30 days
  Frozen  30 days
  Ambient  14 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Creatinine is formed from the metabolism of creatine and phosphocreatine, both of which are principally found in muscle. Thus, the amount of creatinine produced is in large part dependent upon the individual's muscle mass and tends not to fluctuate much from day-to-day.

 

Creatinine is not protein-bound and is freely filtered by glomeruli. All of the filtered creatinine is excreted in the urine.

 

Renal tubular secretion of creatinine also contributes to a small proportion of excreted creatinine. Although most excreted creatinine is derived from an individual's muscle, dietary protein intake, particularly of cooked meat, can contribute to urinary creatinine levels.

 

The renal clearance of creatinine provides an estimate of glomerular filtration rate.

Reference Values

Only orderable as part of a profile. For more information see:

-NMH24 / N-Methylhistamine, 24 Hour, Urine

-RB24 / Retinol-Binding Protein, 24 Hour, Urine

-A124 / Alpha-1-Microglobulin, 24 Hour, Urine

 

Normal values mg per 24 hours:

Males: 930-2955 mg/24 hours

Females: 603-1783 mg/24 hours

 

Reference values have not been established for patients who are less than 18 years of age.

 

For SI unit Reference Values, see https://www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

Day(s) Performed

Monday through Sunday

Report Available

1 day