Direct Antiglobulin Test (DAT), Specimen Sent to Phlebotomy Laboratory
A direct antiglobulin test, also called a direct Coombs test, checks for antibodies or complement attached to red blood cells.
["The DAT helps evaluate immune-mediated red blood cell damage, especially after a transfusion or with unexplained anemia."]
Key facts at a glance
- LOINC
- 89264-6
- Short code
- Date spec was sent to PH lab
- Synonyms
- Date spec was sent to PH lab
- Category
- liver
- 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
What is this test?
The direct antiglobulin test (DAT), or direct Coombs test, is a blood test used to look for antibodies or complement bound to the surface of red blood cells. These substances can cause the immune system to destroy red blood cells.
Why might I need this test?
A DAT may be ordered for unexplained anemia, jaundice, dark urine, or symptoms suggesting hemolysis. It is also commonly used to investigate a suspected blood transfusion reaction or to screen donated blood.
How is the test performed?
A blood sample is collected and examined in the laboratory using a method that detects antibodies or complement attached to red blood cells. If the specimen must be sent to a specialized laboratory, the collection and transport instructions of that laboratory apply.
How do I prepare for the test?
No fasting or special diet is usually required. Tell the healthcare team if the test is connected to a recent transfusion because the sample may need to be collected within a specified time or handled according to transfusion-service procedures.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive DAT means immunoglobulin or complement was detected on red blood cells, but it does not by itself prove that the cells are being destroyed. When interpreted with blood counts, other laboratory results, and your symptoms, it can help identify immune hemolytic anemia, a transfusion reaction, or certain medication-related effects.
Short name
Direct Antiglobulin Test (DAT)
Frequently asked questions
Is the direct antiglobulin test the same as an indirect Coombs test?
Does a positive result always mean I have hemolytic anemia?
Does this test require fasting or take a long time?
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