OSMOLALITY, BLOOD

Mnemonic

OSMOS

Specimen Collection Requirements

Collect

Acceptable Samples: Serum or Li Heparin plasma
Collect 1 SST, plain red, or PST Tube

Heparin tubes should be at least ½ full.
 

Handling

Allow serum to clot completely at room temperature (minimum: 30 minutes). Centrifuge and separate serum or plasma from cells ASAP.
                 

Preferred Volume

0.5 mL

Minimum Volume

0.2 mL

Transport

Refrigerated (2-8°C)

Rejection Criteria

Samples that do not meet SHS labeling requirements.
Samples collected in containers other than the types listed above.
Samples not stored or shipped at proper temperature.
Moderately hemolyzed serum or plasma samples.
 

Stability

AFTER SEPARATION FROM CELLS: 

Serum
Ambient(15 – 25 °C): 2 days
Refrigerated (2 - 8°C): 8 days 
Frozen (at or below -20°C): 7 days

Plasma
Ambient(15 – 25 °C): 3 days
Refrigerated (2 - 8°C): 3 days 
Frozen (at or below -20°C): 7 days
 

Testing Information

Performed

7 days/week

Method

Freezing Point Depression

Referral Lab

Samaritan Health Services Laboratories-GSRMC

Reference Values

Reference Values

Serum/Plasma Osmolality
                < 72 hours: 266 – 295 mOsm/kg H2O
                ≥ 72 hours – 60 years: 275 – 295 mOsm/kg H2O
                > 60 years: 280 – 301 mOsm/kg H2O

CPT Codes

83930

Last Updated: Friday, December 18, 2020 02:34:47 PM