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HelpOrder Code LAB1124 Osmolality, Random, Urine
Additional Codes
Mayo Test Code UOSMU
Epic Test Code: LAB1124
Reporting Name
Osmolality, UUseful For
Assessing the concentrating and diluting ability of the kidney
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Required
Supplies: Urine Tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 5 mL
Collection Instructions: Collect a random urine specimen
Specimen Minimum Volume
1 mL
Reference Values
0-11 months: 50-750 mOsm/kg
≥12 months: 150-1,150 mOsm/kg
CPT Code Information
83935
Method Description
Measurement of the freezing point of urine is the most widely used principle in osmometers. The extent of lowering below 0° C (the freezing point of water) is a function of the concentration of substances dissolved in the urine. By definition 1 milliosmole per kilogram lowers the freezing point 0.001858° C.(Schindler EI, Brown SM, Scott MG: Electrolytes and blood gases. In: Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed.2018:610-612)
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
Freezing Point Depression
Specimen Type
UrineSpecimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 7 days |
| Frozen | 7 days |
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Day(s) Performed
Monday through Sunday