NESTROFT Test (Naked Eye Single Tube Red Cell Osmotic Fragility Test) – BC148
🧬 Thalassemia Screening TestReport: Next day Evening (Except Sunday)
Sample Type: Blood (EDTA)
Test Code: BC148
The NESTROFT Test is a simple, rapid, and low-cost blood screening test for Beta-Thalassemia Trait (also known as Beta-Thalassemia Minor). The name stands for Naked Eye Single Tube Red Cell Osmotic Fragility Test. It is not a definitive diagnostic test but a highly effective screening tool used in population-wide programs.
✔ A fast and inexpensive screening test for Beta-Thalassemia Trait.
✔ Ideal for pre-marital screening, pre-conception screening, and antenatal screening.
✔ A positive result indicates a high likelihood of being a carrier and requires a confirmatory test.
✔ Performed by a skilled laboratory technician at a specialized diagnostic center.
How Does the NESTROFT Test Work?
This test relies on the principle of osmotic fragility. Red blood cells are placed in a specific, mild salt solution (0.36% saline). The fragility of the cells determines the outcome:
- Normal Red Blood Cells: In this specific solution, normal red blood cells are fragile and will absorb water, swell, and burst (hemolysis). This makes the solution clear and transparent.
- Thalassemic Red Blood Cells: The red blood cells of a person with Beta-Thalassemia Trait are smaller (microcytic) and have a different surface-to-volume ratio. This makes them more resistant to osmotic stress. They do not burst in the solution, causing it to remain cloudy or turbid.
A technician can read the test with the "naked eye" by simply trying to read text through the test tube. If the text is clear, the test is negative. If the text is blurred or invisible due to cloudiness, the test is positive. This indicates a high probability that the person is a Thalassemia carrier.
Why is this Screening Important?
Thalassemia Trait is a carrier state; the person is usually healthy and has no symptoms. However, if two carriers (a couple who both have Thalassemia Trait) have a child, there is a 25% chance with each pregnancy that the child will inherit two abnormal genes, resulting in Thalassemia Major, a severe and life-threatening form of anemia that requires lifelong blood transfusions.
The NESTROFT test is the first step in identifying carriers to allow for genetic counseling and informed family planning. A positive NESTROFT result is not a final diagnosis and must be confirmed with a more advanced laboratory test, such as HPLC (High-Performance Liquid Chromatography), which identifies the exact types of hemoglobin in the blood.
Frequently Asked Questions (FAQ)
NESTROFT stands for Naked Eye Single Tube Red Cell Osmotic Fragility Test. It's a simple screening test for Beta-Thalassemia Trait.
A positive result means your red blood cells were resistant to lysis, which is a characteristic of Beta-Thalassemia Trait. It means you are likely a carrier. You must get a confirmatory test, like HPLC, to be certain.
No. A positive NESTROFT test is screening for the trait (carrier state), not the disease. People with Thalassemia Trait are generally healthy and do not have a disease, but they can pass the gene to their children.
A negative NESTROFT test means you are very unlikely to be a Beta-Thalassemia carrier. However, it does not rule out other hemoglobin abnormalities like Alpha-Thalassemia. Your doctor at the diagnostic center will guide you.
No, fasting is not required for this blood test.