Osmotic Fragility of RBCs Lab 5

What is the primary purpose of the osmotic fragility test?

What happens to a cell when it is placed in a hypotonic solution?

Which of the following diseases is associated with increased osmotic fragility?

What is the term for a solution that is more concentrated than the cell?

What is the purpose of performing an osmotic fragility test on infants?

What is the result of a cell being placed in a hypertonic solution?

What is the term for the movement of molecules from a less concentrated solution to a more concentrated solution?

Which of the following diseases is associated with decreased osmotic fragility?

Osmosis and Osmotic Fragility

Osmosis is a process where molecules of a solvent pass through a semi-permeable membrane from a less concentrated solution to a more concentrated one.

Osmotic Fragility Test (OFT)

The OFT measures erythrocyte resistance to hemolysis when exposed to varying levels of dilution of a saline solution.
The test is performed by subjecting a sample of red blood cells to osmotic stress in a hypotonic solution.
OFT is used to aid in the diagnosis of diseases associated with RBC membrane abnormalities.

Diseases Linked to Osmotic Fragility

Increased osmotic fragility is linked to diseases such as:
- Hereditary spherocytosis
- Hypernatremia
Decreased osmotic fragility is linked to diseases such as:
- Chronic liver disease
- Iron deficiency anemia
- Thalassemia
- Hyponatremia
- Polycythemia vera
- Sickle cell anemia after splenectomy

Hypotonic and Hypertonic Solutions

Hypotonic solution: a solution that is less concentrated than the cell, causing water to enter the cell and leading to swelling and potential bursting.
Hypertonic solution: a solution that is more concentrated than the cell, causing water to leave the cell and leading to dehydration and cell death.

Purpose of Osmotic Fragility Test

Doctors may order OFT for infants with a family history of thalassemia or hereditary spherocytosis.

Learn about osmosis and the osmotic fragility test used to measure erythrocyte resistance to hemolysis. This lab exercise explains the concept of osmosis and its application in the osmotic fragility test.