Test Code ROSM Osmolaity, Urine
Specimen and Container/Tube
Specimen Type: Urine, Random Collection
Preferred Specimen: Sterile Plastic Container
Other Acceptable specimens: Sterile Clean Glass Container
Specimen Stability
Storage Temperature |
Stability |
Room temperature |
8 hours |
Refrigerated |
7 days |
Frozen |
Not Applicable |
Collection Instructions
- Collect specimen per standard laboratory collection procedures.
- No preservatives or additives.
Specimen Handling and Transport Instructions
UCMC Onsite Instructions:
- Collect specimen per standard collection procedure and send to laboratory immediately.
- No preservatives or additives.
UCMC Offsite and UC MedLab Outreach Instructions:
- No preservatives or additives
- Aliquot urine into plastic tube containing a minimum of 0.2 mL of specimen.
- Urine samples must then be sent refrigerated at 2-8oC.
Rejection Criteria
- Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits.
- Specimens that are collected with preservatives or additives.
- Specimens that have been stored at room temperature for extended periods (>8 hours).
Reference Values
Test |
Age |
Sex |
Reference Range |
Osmolality, Urine |
All |
All |
500 - 800 mOsm/kg |
Critical Values
Not applicable
Turnaround Time
Turnaround times are relative to the time the specimen is received in the test laboratory.
STAT Turnaround Time: 1 hour
Routine Turnaround Time: 4 hours
Testing Schedule: 24/7
Clinical Indications
Useful in evaluating increased and decreased urine output. Serum osmolality is often useful to interpret urine osmolality.
Test Components
Osmolality, Urine
Methodology
Freezing Point Depression, Osmometry
CPT Codes
83935
LOINC Codes
TBD
Synonyms/Keyword Search
N/A
Additional Information
Not applicable
Last Review Date
6/4/25
Volume
Preferred Volume: 2.0 mL
Minimum Volume: 0.5 mL