Test Directory

• Osmotic Fragility, RBC
• Osmotic Fragility, 0.50 g/dL NaCl
• Osmotic Fragility, 0.60 g/dL NaCl
• Osmotic Fragility, 0.65 g/dL NaCl
• Osmotic Fragility, 0.75 g/dL NaCl

Evaluating suspected hereditary spherocytosis-associated hemolytic anemia.

Confirming or detecting mild spherocytosis.

Specimen Type: Whole Blood

Collection Container: Lavender Top (EDTA)

Desired Specimen Volume: 4 mL (Patient and Control)

A control specimen is required for testing alongside the patient's specimen.

1. Collect Monday - Friday ONLY. No holidays or day before a holiday.
2. Collect a lavender top (EDTA) tube via venipuncture for the patient.
3. Collect a lavender top (EDTA) tube via venipuncture for the control.
4. A control specimen must be drawn from a normal (healthy), unrelated, nonsmoking person at the same time as the patient.
5. Clearly hand write “normal control” on the outermost label for the control sample.

1. Transport 4 mL of whole blood for the patient in the original collection container. Do not aliquot.
2. Transport 4 mL of whole blood for the control in the original collection container. Do not aliquot.
3. Rubber band patient specimen and control vial together. The control and patient specimen must be handled in the same manner from specimen collection to receipt in the testing laboratory.

Transport to the laboratory refrigerated. 

• Gross hemolysis
• Clotted blood

See patient report.

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 red blood cells (RBC) enzyme deficiencies.

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

• FRAGILITY, OSMOTIC (RBC)
• RBC Fragility, Erythrocytes
• Red Cell Fragility