Abogroupbldcfm
This test determines your blood type (A, B, AB, or O) using a confirmatory method to ensure accurate results.
{"Identifies your ABO blood group (A, B, AB, or O)","Essential for safe blood transfusions and pregnancy care","Results are permanent and do not change throughout life"}
Key facts at a glance
- LOINC
- 57743-7
- Short code
- ABO
- Synonyms
- ABO Group Bld Cfm
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA lavender-top tube (K2-EDTA or K3-EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- confirm
- CPT
- 86900
- SNOMED
- 365589006
- Specimen volume
- 3-5 mL whole blood
- Stability
- Room temperature (20-25°C): 72 hours; Refrigerated (2-8°C): 7 days. Do not freeze. Transport upright to prevent cell damage.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 1–24 hours
- Order
- routine
What is this test?
The ABO blood type test is a laboratory test that determines which of the four ABO blood groups you belong to: A, B, AB, or O. The 'confirmatory method' means the test includes additional verification steps to ensure the result is accurate, which is especially important before blood transfusions or during pregnancy.
How is the test performed?
A healthcare professional will draw a small sample of blood from a vein in your arm using a needle. The blood sample is then tested in a laboratory to identify the antigens (substances that trigger immune responses) on your red blood cells and the antibodies in your plasma. The confirmatory method may involve multiple steps to verify the results, ensuring accuracy for critical medical decisions.
What do the results mean?
Your blood type is determined by the combination of antigens on your red blood cells: Type A has A antigens, Type B has B antigens, Type AB has both A and B antigens, and Type O has neither. Your plasma contains antibodies against the antigens you don't have. This information is critical for matching blood donors and recipients during transfusions.
Reference range
Results reported as A, B, AB, or O. Reference range indicates presence of expected agglutination pattern; each individual should have measurable ABO antigens on red blood cells and corresponding antibodies in serum/plasma.N/A
No special preparation required. Patient identification must be verified at time of collection. Label specimen immediately with two patient identifiers per CLIA requirements.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Does my blood type change over time?
Is this test painful?
Do I need to fast before this test?
Why is the confirmatory method used?
What is the Rh factor?
Sources
- 1
- 2May Clinic - Blood TypesSource
- 3AABB - Blood TransfusionSource
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