Hemoglobin A2 Fraction (High-Performance Liquid Chromatography)
This test measures the percentage of hemoglobin A2, a form of hemoglobin found in your blood that carries oxygen. It helps assess how well your body is producing the normal form of hemoglobin (HbA1c).
["HbA2 helps diagnose and monitor conditions like beta-thalassemia and certain types of anemia."]
Key facts at a glance
- LOINC
- 4550-0
- Short code
- Hgb A2 Bld Column Chrom-sCnc
- Synonyms
- Hgb A2 Bld Column Chrom-sCnc
- Category
- hematology
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 12
- Ref high
- 17.5
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- chromatography-column
- CPT
- 85018
- SNOMED
- 900000000000003004
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why is this test done?
Your healthcare provider may order an HbA2 test if you have symptoms of inherited blood disorders, such as fatigue, pale skin, or frequent infections. It’s also used to monitor people with known genetic conditions affecting hemoglobin production, like thalassemia or sickle cell trait.
How is the test collected?
A small amount of blood is drawn from a vein in your arm, similar to a regular blood test. The sample is processed to separate hemoglobin types for analysis.
What does the test result mean?
Results are reported as a percentage of total hemoglobin. Higher-than-normal levels may indicate conditions like beta-thalassemia, while lower levels could suggest other blood disorders. Your doctor will interpret results in the context of your medical history and symptoms.
How often is this test done?
Frequency depends on your medical condition. People with thalassemia or related disorders may have HbA2 tests regularly to track changes in hemoglobin types over time.
Reference range
Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: HbA2 is a key marker for inherited hemoglobin disorders. Elevated HbA2 levels often point to beta-thalassemia or other genetic conditions affecting red blood cell production. Monitoring HbA2 helps manage symptoms, prevent complications, and guide treatment decisions, such as blood transfusions or iron chelation therapy.
Short name
HbA2
Frequently asked questions
What does an abnormal HbA2 result mean?
How does HbA2 differ from HbA1c?
Can lifestyle changes affect HbA2 levels?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy