Test library
G6PD Test
The quantitative G6PD test measures the activity of glucose 6-phosphate dehydrogenase, an enzyme that protects red blood cells from oxidative stress. Low activity can point to G6PD deficiency, which is linked to a form of hemolytic anemia.
Order Glucose 6-Phosphate Dehydrogenase (G6PD) Test, Quantitative
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Order Glucose 6-Phosphate Dehydrogenase (G6PD) Test, Quantitative- Typical turnaround
- 1-3 business days
- Starting price
- From $158
- Results
- Confidential, online
Quick answer
The quantitative G6PD test measures how much glucose 6-phosphate dehydrogenase activity is present in a blood sample. This enzyme helps red blood cells handle oxidative stress, and reduced activity can make them break down more easily under certain conditions. The test supports the evaluation of a suspected G6PD deficiency and is interpreted with a blood count and clinical history.
What this test measures
Glucose 6-phosphate dehydrogenase is an enzyme in the red blood cell pathway that regenerates molecules needed to neutralize oxidative damage. When activity is low, red blood cells are more vulnerable to stresses such as infection, certain foods, or some medications, and they can rupture in a process called hemolysis. The result is reported as a quantitative activity level rather than a simple positive or negative.
A blood sample is drawn from a vein, and the laboratory measures enzyme activity in the red cells. Because a recent episode of hemolysis or a recent blood transfusion can distort the result, the ordering provider should be told about any such event. In some situations, testing may be repeated once the blood count has stabilized.
A low activity level supports a diagnosis of G6PD deficiency, but results are always interpreted with the full clinical picture, including hemoglobin, bilirubin, and evidence of red cell breakdown. A qualified healthcare provider determines what the value means for an individual and whether additional testing is needed.
- Glucose 6-phosphate dehydrogenase (G6PD) enzyme activity
- Hemoglobin
- Hematocrit
- Reticulocyte count
- Total bilirubin
- Lactate dehydrogenase (LDH)
- Haptoglobin
- Complete blood count
Why people order this test
- Evaluate a suspected G6PD deficiency
- Investigate hemolytic anemia or unexplained red blood cell destruction
- Check enzyme activity before certain treatments are considered
- Assess a family history of G6PD deficiency
- Follow up on unexplained jaundice or anemia
- Provide a baseline level when a deficiency is already known
How to prepare
No fasting is typically required. A blood sample is drawn from a vein, and because a recent transfusion or hemolytic episode can affect the reading, tell the ordering provider about any recent transfusions or rapid drops in blood count.
Understanding your results
Results are usually available within one to three business days. The report gives a quantitative enzyme activity level, and low activity supports a G6PD deficiency. A qualified healthcare provider interprets the value together with the blood count and clinical history.
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Frequently Asked Questions
What does the G6PD test measure?
It measures the activity of glucose 6-phosphate dehydrogenase, an enzyme that protects red blood cells from oxidative damage. A low level suggests the enzyme is not working at full capacity.
Why is the quantitative version used?
A quantitative test reports the actual level of enzyme activity rather than only a yes or no result. That detail helps clinicians gauge how much activity is present.
Can a recent blood transfusion affect the result?
Yes. Transfused red cells can change the measured activity, so testing may be delayed or repeated after a transfusion or a hemolytic episode.
Do I need to fast?
Fasting is not usually required for a G6PD test. Follow any instructions provided with your order.
How long do results take?
Most results are reported within one to three business days.
Ready to get tested?
Order online and visit a collection site near you, or choose a mail-in kit. No referral and no insurance required.
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