OSMOLALITY, SERUM

Test Code

OSM

CPT Codes
83930

Preferred Specimen

1 Gold tube (gel separator)

Minimum Volume

0.2 mL

Other Acceptable Specimens

or 1 Green tube (Lithium Heparin)

Instructions

Centrifuge for complete separation of serum or plasma and red cells. If gel barrier tube is not used, aliquot plasma into a transfer tube. Refrigerate until tested.

Transport Temperature

Refrigerate

Specimen Stability

15-30ºC up to 3 hours
2-8ºC up to 3 days
Frozen samples stable up to 7 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Lipemic or hemolyzed specimen

Methodology
Freezing point depression

Setup Schedule

M, T, W, Th, F, Sa, Sun

Report Available

Within 24 hours of receipt at the performing laboratory.

Reference Range

273-309 mOsm/kg

Clinical Significance

Measure and assess anion gap and ingestion of abnormal substances like drugs or ethanol

Performed By
Alverno Laboratories

Performing Laboratory
Alverno Central Lab
NCH15 (Chemistry, Manual)

Last Updated: June 9, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.