Definition of Mononucleosis spot test:

The mononucleosis spot test looks for two antibodies in the blood that indicate infection with the Epstein-Barr virus (EBV).

How the test is performed:

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

How to prepare for the test:

No special preparation is necessary.

How the test will feel:

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. You may feel throbbing at the site of the needle stick for a few minutes after the blood is taken.

Why the test is performed:

Sometimes, when the body reacts to an infection, antibodies are made that have nothing to do with the germ. These are called heterophile antibodies.

This test looks for such antibodies. It is used to diagnosis infectious mononucleosis, a disease caused by the Epstein-Barr virus (EBV). About 1 week after the onset of the disease, many patients develop heterophile antibodies. Antibodies reach peak levels in 2 - 5 weeks and may persist for up to 1 year. However, a small number of persons with mononucleosis may never develop such antibodies.