Osmolality, 24-Hour Incubation, NaCl, and Red Blood Cell Fragility Panel
This panel combines a 24-hour incubation step with sodium chloride (NaCl) testing and red blood cell fragility assessment, typically used to evaluate how red blood cells behave under controlled conditions.
["This is a specialized laboratory panel that evaluates blood cell stability and osmolality-related properties after prolonged incubation."]
Key facts at a glance
- LOINC
- 34967-0
- Short code
- OF .20% NaCl 24h Inc NFr RBC
- Synonyms
- OF .20% NaCl 24h Inc NFr RBC
- Category
- electrolyte
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85041
- SNOMED
- 900000000000003001
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What This Panel Measures
The panel involves an osmolality measurement after a 24-hour incubation, exposure to sodium chloride solutions, and assessment of red blood cell fragility (how easily red blood cells break apart). These measurements together help characterize the physical resilience of red blood cells.
How the Test Is Performed
A blood sample is collected and portions are incubated for 24 hours. Sodium chloride is added or used as a buffer solution, and the samples are then analyzed for osmolality and red blood cell fragility. The incubation step allows the lab to observe changes that may not appear immediately.
Specimen and Timing
The test requires a blood specimen and involves a timed 24-hour incubation before final analysis. Follow your lab's instructions for specimen collection and note that results may take longer to report because of the incubation period.
What Results May Mean
Changes in osmolality or increased red blood cell fragility after incubation can indicate differences in red blood cell membrane stability or fluid balance at the cellular level. Because this is a specialized test, your healthcare provider will interpret results in the context of your symptoms and other findings.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This panel is not a routine screening test; it is used in specialized settings to assess red blood cell stability and osmolality under stress conditions such as prolonged incubation and sodium chloride exposure. Abnormal findings may point toward membrane or osmotic disorders, but results must be interpreted by a clinician alongside other testing and clinical history.
Frequently asked questions
Why is a 24-hour incubation needed?
Does this test require special preparation?
Can I get results quickly?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy