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Reverse Antibody Grouping Blood Test (ABO Blood Grouping with Reverse Typing)

Published: August 9, 2026Updated: August 16, 2026

This test helps determine your blood type by checking for antibodies in your blood that react with known antigens on red blood cells.

Quick summary

["Your blood type is crucial for safe blood transfusions and pregnancy care."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
1303-7
Short code
Reverse ABO Group Bld
Synonyms
Reverse ABO Group Bld
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is Done

Doctors may order this test during blood donation screening, before surgeries requiring transfusions, or if you have unexplained anemia, jaundice, or bleeding disorders. It ensures compatibility for transfusions or helps diagnose potential blood-related conditions.

How the Test Works

A small blood sample is taken and mixed with known red blood cell antigens. If antibodies in your blood react (clumping or agglutination), it confirms your blood type. This method is called reverse typing because it identifies antibodies rather than antigens directly.

Sample Collection

Whole blood is collected via a simple venipuncture (needle in your arm). The sample is processed to separate plasma for antibody testing.

What to Expect

You may feel slight discomfort or bruising at the needle site. Most people return to normal activities immediately after. No special preparation is needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is vital for preventing transfusion reactions, ensuring compatibility between donor and recipient blood. It also helps diagnose conditions like autoimmune hemolytic anemia or Rh incompatibility in pregnancy, which can affect fetal health.

Short name

Reverse ABO Blood Group

Frequently asked questions

How long does it take to get results?
Results are typically available within 1–2 business days, depending on lab processing times.
What does a positive reaction mean?
A positive reaction (visible clumping) indicates the presence of antibodies that match your blood type. For example, if clumping occurs with red blood cells labeled ‘A,’ your blood type is likely O (no A antigen).
Can I donate blood if this test is abnormal?
If your test shows unexpected antibodies, you may need further evaluation, but some blood types (like O negative) are universally compatible. Always follow your donor center’s guidelines.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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