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25541 Osmotic Fragility, Erythrocytes (FRAG)

Osmotic Fragility, Erythrocytes (FRAG)
Test Code: FRAGSO
Synonyms/Keywords
​FRAGILITY, OSMOTIC (RBC), RBC Fragility, Erythrocytes, Red Cell Fragility
Test Components
​Osmotic Fragility, Osmotic Fragility on Control Sample
Useful For

​Evaluation of suspected heredity spherocytosis associated hemolytic anemia

Confirming or detecting mild spherocytosis

Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
​A whole blood EDTA specimen and a control specimen are required.  Label clearly on outermost label "normal control" sample.
​No ​Whole Blood ​EDTA Lavender Top Tube (LTT) ​4 mL ​2 mL
​Control Sample ​Whole Blood ​EDTA Lavender Top Tube (LTT) ​4 mL ​2 mL
Collection Processing Instructions

Specimens must arrive within 72 hours of draw.

Immediately refrigerate specimen after draw to 0 to 4 degrees C. Do not aliquot or let samples freeze. Ship specimens in original tubes.  Specimen and control should be stored and transported together at refrigerate temperature.

Patient age and sex are required.

Specimen Stability Information
Specimen Type Temperature Time
​Whole Blood (control) ​Refrigerate ​72 hours
​Whole Blood (patient) ​Refrigerate ​72 hours
Rejection Criteria
​Frozen specimen
​Gross hemolysis
​Clotted blood

 

Interference

Spherocytosis of any cause will result in increased osmotic fragility. Infrequently, other congenital hemolytic disorders may also be associated with positive results, as in patients with congenital nonspherocytic hemolytic anemia due to RBC enzyme deficiencies.

Patients with an immunohemolytic anemia, or who have recently received a blood transfusion may also have increased RBC lysis.

The shipping control specimen is required to adequately interpret these cases, as temperature extremes can increase the fragility of the specimen and cause false-positive results.

Resulting Cautions: Osmotic fragility results will be reported if the shipping control is normal.

If the shipping control is abnormal and the osmotic fragility results on the patient are within normal range, the results will be reported; however, a comment will be added to the report indicating that the shipping control was not entirely satisfactory.

The test will be cancelled if the patient specimen and shipping control are both abnormal.

Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories ​Monday through Saturday ​2-5 days ​Osmotic Lysis
Reference Lab
Test Information

​Spherocytes are osmotically fragile cells that rupture more easily in a hypotonic solution than do normal RBCs. Because they have a low surface area:volume ratio, they lyse at a higher osmolarity than do normal discocyte (RBCs). Cells that have a larger surface area:volume ratio, such as target cells or hypochromic cells are more resistant to lysing. After incubation, an increase in hemolysis is seen in spherocytes. Hereditary spherocytosis typically has greater number of spherocytes than other causes of spherocytosis. Therefore, the degree of lysis is usually more pronounced, but this is not always the case. Some rare disorders can also cause marked fragility and hereditary spherocytosis cases can display moderate fragility.

Reference Range Information

> or =12 months:
0.50 g/dL NaCl (unincubated): 3-53% hemolysis
0.60 g/dL NaCl (incubated): 14-74% hemolysis
0.65 g/dL NaCl (incubated): 4-40% hemolysis
0.75 g/dL NaCl (incubated): 1-11% hemolysis

Reference values have not been established for patients who are <12 months of age.

Interpretation
​An interpretive report will be provided
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85557
Synonyms/Keywords
​FRAGILITY, OSMOTIC (RBC), RBC Fragility, Erythrocytes, Red Cell Fragility
Test Components
​Osmotic Fragility, Osmotic Fragility on Control Sample
Ordering Applications
Ordering Application Description
​Centricity ​Osmotic Fragility, RBC
​Cerner ​Osmotic Fragility, RBC
​Clinical Order Manager ​Osmotic Fragility, RBC
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
​A whole blood EDTA specimen and a control specimen are required.  Label clearly on outermost label "normal control" sample.
​No ​Whole Blood ​EDTA Lavender Top Tube (LTT) ​4 mL ​2 mL
​Control Sample ​Whole Blood ​EDTA Lavender Top Tube (LTT) ​4 mL ​2 mL
Collection Processing

Specimens must arrive within 72 hours of draw.

Immediately refrigerate specimen after draw to 0 to 4 degrees C. Do not aliquot or let samples freeze. Ship specimens in original tubes.  Specimen and control should be stored and transported together at refrigerate temperature.

Patient age and sex are required.

Specimen Stability Information
Specimen Type Temperature Time
​Whole Blood (control) ​Refrigerate ​72 hours
​Whole Blood (patient) ​Refrigerate ​72 hours
Rejection Criteria
​Frozen specimen
​Gross hemolysis
​Clotted blood

 

Interference

Spherocytosis of any cause will result in increased osmotic fragility. Infrequently, other congenital hemolytic disorders may also be associated with positive results, as in patients with congenital nonspherocytic hemolytic anemia due to RBC enzyme deficiencies.

Patients with an immunohemolytic anemia, or who have recently received a blood transfusion may also have increased RBC lysis.

The shipping control specimen is required to adequately interpret these cases, as temperature extremes can increase the fragility of the specimen and cause false-positive results.

Resulting Cautions: Osmotic fragility results will be reported if the shipping control is normal.

If the shipping control is abnormal and the osmotic fragility results on the patient are within normal range, the results will be reported; however, a comment will be added to the report indicating that the shipping control was not entirely satisfactory.

The test will be cancelled if the patient specimen and shipping control are both abnormal.

Useful For

​Evaluation of suspected heredity spherocytosis associated hemolytic anemia

Confirming or detecting mild spherocytosis

Test Components
​Osmotic Fragility, Osmotic Fragility on Control Sample
Reference Range Information

> or =12 months:
0.50 g/dL NaCl (unincubated): 3-53% hemolysis
0.60 g/dL NaCl (incubated): 14-74% hemolysis
0.65 g/dL NaCl (incubated): 4-40% hemolysis
0.75 g/dL NaCl (incubated): 1-11% hemolysis

Reference values have not been established for patients who are <12 months of age.

Interpretation
​An interpretive report will be provided
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories ​Monday through Saturday ​2-5 days ​Osmotic Lysis
Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85557
For most current information refer to the Marshfield Laboratory online reference manual.