Osmotic Fragility Test, Blood

About the test :

The Osmotic Fragility Test (OFT) measures how easily red blood cells (RBCs) burst (hemolyze) when exposed to varying concentrations of salt (hypotonic) solutions.

• It evaluates the stability and integrity of red blood cell membranes.
• Helps detect abnormal red blood cell shapes or fragility that can lead to hemolytic anemia.

Why the Test Is Ordered

1. Suspected hereditary red blood cell disorders

• Spherocytosis (RBCs are sphere-shaped and fragile)
• Elliptocytosis (RBCs are elliptical)

2. Unexplained anemia

• Hemolytic anemia (RBCs destroyed faster than they are made)
• Unexplained jaundice

3. Pre- or post-splenectomy evaluation

• To confirm diagnosis of hereditary spherocytosis before surgery

4. Investigate hemolysis from other causes

• Autoimmune hemolytic anemia
• Certain infections or medications

Clinical Significance

• Helps diagnose specific red blood cell membrane disorders
• Guides treatment decisions for hemolytic anemia
• Can indicate need for further genetic or hematology testing