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Test Code USPG Specific Gravity, Random, Urine

Additional Codes

Epic: LAB2448

Specimen Required

Specimen Type: Urine

Collection Container/Type

Preferred: Clear top (no additive)

Submission Container/Tube: Clear top (no additive)

Specimen Volume: 5 mL

Collection Instructions: 

  1. Collect a random urine specimen.
  2. Keep specimen refrigerated.
  3. Specimens should be tested within 24 hours.

Specimen Minimum Volume

1 mL

Specimen Stability

Room temperature: Unaccpetable

Refrigerated: 24 hours

Frozen: Not defined

Reference Range


Rejection Due To

Unlabeled, mislabeled, wrong tube type, hemolyzed, QNS, exceeds specimen stability requirements.

Day(s) and Time(s) Performed


Report Available

Same day

Clinical Significance

Specific gravity (SG), the ratio of the mass of a solution compared to the mass of an equal volume of water, is an estimate of the concentration of substances dissolved in the solution.


Urine SG can be used to assess the kidney’s ability to concentrate or dilute urine. However, because protein, glucose, and contrast dye have molecular masses that are relatively large compared to other major components of urine (eg, sodium, chloride, potassium), they disproportionately affect SG. In these cases, urine osmolality is a better measure of urine concentration.

Method Name