Mononucleosis (mono) tests are blood tests to look for antibodies usually caused by the Epstein-Barr virus (EBV). The antibodies are made by the immune system to fight the infection.
Mono tests include:
- EBV antibody test. This test can detect different types of antibodies to help determine whether you were infected recently or sometime in the past.
- Rapid mono test. Rapid mono testing can usually detect antibodies in 2 to 6 weeks after a person is infected. A rapid mono test may be done in some health care settings, but it's possible for the results to be negative (false negative) in the early days of the infection.
Why It Is Done
Epstein-Barr virus (EBV) antibody testing is done to diagnose mono. The EBV antibody test can help determine whether you have ever been infected with the virus and whether the infection has been recent.
The rapid mono test is done to help diagnose a recent mono infection. A rapid mono test may be done in some health care settings, but it's possible for the results to be negative (false negative) in the early days of the infection.
How To Prepare
In general, there's nothing you have to do before this test, unless your doctor tells you to.
How It Is Done
The Epstein-Barr antibody test is done on a blood sample taken from your vein. The rapid mono test is done on a small sample of blood taken from your fingertip or from a vein.
Blood test from a vein
A health professional uses a needle to take a blood sample, usually from the arm.
Blood test from a finger stick
For a finger-stick sample, the health professional will puncture the skin on your middle or ring finger with a small tool called a lancet. Then they'll collect a small amount of blood.
How It Feels
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
Risks
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
Results
Epstein-Barr antibody testing
The results of an EBV antibody test are usually ready within 3 days.
The results of the antibody test to detect Epstein-Barr virus (EBV) are usually reported as positive (antibodies are present) or negative (antibodies are not present).
The EBV antibody test can also detect the type of antibodies (immunoglobulins) present in the blood. The type of antibody shows whether the infection is recent or occurred in the past.
Normal (negative):
- No IgM antibody against EBV is present.
Abnormal (positive):
- The antibody IgM against EBV is present.
Rapid mono test
A rapid mono test may be done in some health care settings, but it's possible for the results to be negative (false negative) in the early days of the infection. The results of a rapid mono test are usually ready within 1 hour.
Normal (negative):
- The blood sample does not form clumps (no heterophile antibodies are detected).
Abnormal (positive):
- The blood sample clumps (heterophile antibodies are detected). If the blood sample clumps, you probably have mono.
Credits
Current as of: September 30, 2025
