Hemoglobin A2 Fraction (High-Performance Liquid Chromatography)
This test measures the percentage of a specific type of hemoglobin (HbA₂) in your blood, which is a marker for certain blood disorders.
["HbA₂ helps diagnose and monitor conditions like thalassemia."]
Key facts at a glance
- LOINC
- 51616-1
- Short code
- Hgb A2+E MFr Bld
- Synonyms
- Hgb A2+E MFr Bld
- 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
- 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
What Is HbA₂?
HbA₂ is a form of hemoglobin that carries oxygen in your red blood cells. While most hemoglobin is made up of HbA₁c (which reflects average blood sugar levels), HbA₂ is a distinct component that can be measured separately. This test is particularly useful for identifying genetic blood disorders that affect hemoglobin production.
Why Might You Need This Test?
Your healthcare provider may order an HbA₂ test if you have symptoms or a family history of thalassemia, sickle cell disease, or other hemoglobinopathies. It may also be used to monitor these conditions in people who already have them.
How Is the Test Performed?
A small blood sample is taken from a vein in your arm. The blood is then analyzed using high-performance liquid chromatography (HPLC), a method that separates and measures different types of hemoglobin.
What Do the Results Mean?
Results are expressed as a percentage of HbA₂ relative to total hemoglobin. Elevated levels may indicate thalassemia or other hemoglobin disorders, while normal levels help confirm the absence of these conditions. Your results will be interpreted by a healthcare professional based on your clinical picture.
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
Short name
HbA₂
Frequently asked questions
How common is this test?
Can HbA₂ levels change with diet or lifestyle?
Is this test painful?
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