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Aborhblddonr

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

A blood test that determines your blood group (A, B, AB, or O) and Rh factor (positive or negative) to ensure safe blood transfusion and pregnancy care.

Quick summary

{"This test identifies your ABO blood type (A, B, AB, or O) and Rh factor (positive or negative)","Results are critical for matching blood donors with recipients during transfusions","Rh status is especially important for pregnant women to prevent complications","The test requires a simple blood sample from a vein","Knowing your blood type can help in emergency medical situations"}

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

Key facts at a glance

LOINC
14577-1
Short code
ABO-Rh
Synonyms
ABO + Rh Bld Donr
Category
chemistry
Sample
whole-blood
Container
EDTA vacutainer tube (purple-top / lavender-top) - minimum 3 mL preferred
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Serological agglutination (tube, slide, or gel card method) using anti-A, anti-B, anti-D (Rh) reagents with reverse grouping using A1 and B reagent cells
CPT
86850 (ABO grouping); 86870 (Rh typing)
SNOMED
365787006 (Blood group); 112144000 (ABO blood group); 27942009 (Rh blood group)
Specimen volume
5-10 mL whole blood (3 mL minimum for pediatric samples)
Stability
Room temperature (20-25°C): 72 hours; Refrigerated (2-8°C): 7 days. Do not freeze. Transport at ambient temperature.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
1–24 hours
Order
routine

What is this test?

The ABO and Rh blood type test is a routine laboratory test that identifies the specific blood group and Rh factor in your blood. Your blood contains antigens (proteins) on the surface of red blood cells that determine your blood type. The test classifies blood into four main groups: A, B, AB, and O, and further identifies whether you are Rh-positive or Rh-negative.

How is the test performed?

A healthcare professional will draw a small blood sample from a vein in your arm using a needle. This sample is then sent to a laboratory where it is mixed with special antibodies to see how your red blood cells react. The results are typically available within a few hours to a day.

Why is this test important for blood donors?

For blood donors, knowing your exact blood type is essential to ensure the safety and effectiveness of blood transfusions. Blood banks carefully screen and type all donated blood to match it with recipients who need transfusions. Using the wrong blood type can cause a dangerous immune reaction called hemolysis, where the recipient's body attacks the donated red blood cells.

Understanding your results

Your ABO blood type indicates which antigens are present 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. The Rh factor indicates whether you have the RhD antigen—Rh-positive means you have it, Rh-negative means you don't. This information determines who can safely receive your donated blood and whose blood you can receive.

Reference range

ABO group: A, B, AB, or O. Rh type: Rh(D) positive or Rh(D) negative. Results must show expected reactivity patterns for forward and reverse grouping to be considered valid.N/A

Specimen: whole-blood

No fasting required. Patient identification must be verified at time of collection. Label specimen tube immediately after collection with two patient identifiers per CLIA/CAP guidelines.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings2

Frequently asked questions

Does it hurt?
You may feel a brief pinch or sting when the needle is inserted to draw blood. Some people may experience mild bruising or soreness afterward, but this typically resolves quickly.
Do I need to fast before this test?
No, you do not need to fast before an ABO and Rh blood type test. You can eat and drink normally before the test.
How often should I know my blood type?
You typically need to know your blood type only once, as it does not change throughout your lifetime. However, if you donate blood regularly, your type will be confirmed with each donation.
What if I'm Rh-negative?
Being Rh-negative means you lack the RhD antigen. If you are a woman of childbearing age and become pregnant, your healthcare provider will monitor you closely if your baby is Rh-positive to prevent complications. Rh-negative individuals can only receive Rh-negative blood in transfusions.
Can I donate blood if I have any blood type?
All blood types are valuable for donation. However, O-negative blood is known as the 'universal donor' type and can be given to anyone, while AB-positive is the 'universal recipient' type and can receive blood from anyone.
  1. 1
    Mayo Clinic - Blood typesSource
  2. 2
    American Red Cross - Blood TypesSource
  3. 3
    MedlinePlus - Blood TypingSource

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