Mononucleosis spot test
A mononucleosis spot test (rapid mono test) is a screening test for mononucleosis. The test detects a type of antibody (heterophil antibody) that forms during certain infections, especially during infection with the Epstein-Barr virus.
For this test, a sample of blood is placed on a microscope slide and mixed with other substances. If heterophil antibodies are present, the blood clumps. This result usually points to a mono infection.
The test can usually find a mono infection in about 2 to 9 weeks after the person has been exposed to the virus. The antibodies are proteins made by the immune system to fight the infection. After they have formed, antibodies usually remain in a person's blood for life.
Why are mononucleosis (mono) tests done?
The rapid mono test is done to help diagnose a recent mono infection.
Epstein-Barr virus (EBV) antibody testing is also done to help 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.
EBV antibody testing is usually done when you have symptoms of infectious mononucleosis and a rapid mono test result is negative. EBV antibody testing may also be done to check for antibodies to EBV when a person has a disease or uses medicine that causes problems with the immune system.
How are mononucleosis (mono) tests done?
The rapid mono test is done on a small sample of blood taken from your fingertip or from a vein. The Epstein-Barr antibody test is done on a blood sample taken from your vein.
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.
Blood test from a vein
A health professional uses a needle to take a blood sample, usually from the arm.
How do you prepare for a mononucleosis (mono) test?
In general, there's nothing you have to do before this test, unless your doctor tells you to.
What do the results of mononucleosis (mono) tests mean?
Rapid mono test
The results of a rapid mono test are usually ready within 1 hour.
Normal (negative): | The blood sample does not form clumps (no heterophil antibodies are detected). |
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Abnormal (positive): | The blood sample clumps (heterophil antibodies are detected). If the blood sample clumps, you probably have mono. |
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 old.
Normal (negative): | No IgM antibody against EBV is present. If the antibody IgG is present, it may mean that you have been exposed to EBV in the past. |
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Abnormal (positive): | The antibody IgM against EBV is present. |
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