Blood Group A/B Antibody Titration (Serum/Plasma)
This test measures the presence and level of antibodies against blood group A and B antigens in your blood, typically drawn from serum or plasma. It helps determine compatibility for blood transfusions or pregnancy-related risks.
Assesses your immune response to A and B blood antigens for safe blood or pregnancy care.
Key facts at a glance
- LOINC
- 50970-3
- Short code
- XXX blood group Ab Titr SerPl AHG
- Synonyms
- XXX blood group Ab Titr SerPl AHG
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- antihuman-globulin
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Blood group compatibility is critical during transfusions or pregnancy to prevent adverse reactions. This test identifies whether you have antibodies that could react against A or B antigens in donor blood or fetal blood, depending on your blood type.
Sample Collection and Preparation
A blood sample is drawn from a vein in your arm. The blood is processed to separate serum or plasma, which is then tested for antibodies. No special preparation is needed, but fasting may be advised depending on your healthcare provider’s instructions.
What the Results Indicate
Results show the concentration of A and B antibodies in your blood. A positive result means you have detectable antibodies, which may affect blood donation eligibility or pregnancy outcomes. A negative result indicates no significant antibodies are present.
Common Uses and Scenarios
This test is often used during blood donation screening, before certain transfusions, or during pregnancy to assess risks of Rh incompatibility or other antibody-related complications.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal antibody levels can lead to complications such as hemolytic disease of the newborn (if antibodies cross the placenta) or transfusion reactions. It’s particularly important for individuals with rare blood types or those who have had previous blood transfusions or pregnancies.
Short name
A/B Antibody Test
Frequently asked questions
What does a positive result mean?
How often should I get this test?
Can I donate blood if I have this test?
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