Duffy Blood Group Antigen (GYPA) Testing (Qualitative)
This test checks for the presence of the Duffy blood group antigen, which is important for understanding your blood type compatibility and potential risk for malaria in certain populations.
["Helps determine your blood type variant that may affect red blood cell protection against malaria."]
Key facts at a glance
- LOINC
- 13309-0
- Short code
- Duffy Group Ag RBC
- Synonyms
- Duffy Group Ag RBC
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85041
- SNOMED
- 900000000000003001
- 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 in Blood Transfusions
The Duffy antigen is a protein found on red blood cells. Some people lack this protein (Duffy-negative), which may offer some protection against malaria. This test helps ensure safe blood transfusions by confirming your specific blood type variant.
How the Test Works
A small blood sample is taken from your arm. The lab uses an immunoassay method to detect the presence or absence of the Duffy antigen on your red blood cells. The result is qualitative—either you have the antigen or you don’t.
What to Expect Before the Test
No special preparation is needed. You may have a slight bruise or soreness at the injection site, but this usually fades quickly. If you’re pregnant or have a history of blood disorders, let your provider know.
What to Expect After the Test
You can return to your normal activities immediately. Watch for signs of infection (like fever or swelling) at the injection site, but these are rare. If you experience unusual bleeding or dizziness, contact your provider.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Duffy-negative individuals (lacking the Duffy antigen) are naturally resistant to malaria, a disease spread by mosquitoes. This test is particularly relevant for travelers to malaria-endemic regions or individuals with a family history of malaria resistance. It also plays a role in rare blood type compatibility issues during transfusions.
Short name
Duffy Blood Type Screening
Frequently asked questions
Why might my doctor order this test?
What does a positive or negative result mean?
Can this test be done at home?
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 17, 2026. · Read our editorial policy