Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Font Size

Mononucleosis Tests


Mononucleosis tests are blood tests to look for antibodies that indicate mononucleosis (mono), which is usually caused by the Epstein-Barr virus (EBV). The antibodies are made by the immune system to fight an infection.

Monospot test

The results of a monospot test are usually ready within 1 hour.

Monospot test
Normal (negative):

The blood sample does not form clumps (no heterophil antibodies are detected).

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 the antibody test to detect Epstein-Barr virus (EBV) may be reported as positive (antibodies are present) or negative (antibodies are not present). Or the test results may be reported in titers.

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. The antibody IgM is only found during the active phase of mono. The antibody IgG can be found later, when you are starting to get better.

The results of an EBV antibody test are usually ready within 3 days.

EBV antibody test 1
Normal (negative):

The titer is less than 1 to 10 (1:10). A titer of less than 1:10 means that you have never been exposed to EBV.

No IgM against EBV is present. If IgG is present, it may mean that you have been exposed to EBV in the past.

Abnormal (positive):

A titer greater than 1 to 10 (1:10) but less than 1:320 usually means that you have been infected with EBV at some time in the past.

A titer of 1:320 or greater means that you have an active EBV infection (mononucleosis).

IgM against EBV is present.

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

  • Having an EBV antibody test within the first few weeks of becoming infected with EBV. This may lead to a false-negative result. If the first test does not indicate mono but you still have symptoms, the test may be repeated.
  • Other infection or disease, such as cytomegalovirus (CMV), leukemia or lymphoma, rubella, hepatitis, or lupus. Although the symptoms of these infections and diseases are similar to mono, the monospot test usually will be negative.
  • Having a weakened immune system.

WebMD Medical Reference from Healthwise

Last Updated: November 14, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

Hot Topics

WebMD Video: Now Playing

Click here to wach video: Dirty Truth About Hand Washing

Which sex is the worst about washing up? Why is it so important? We’ve got the dirty truth on how and when to wash your hands.

Click here to watch video: Dirty Truth About Hand Washing

Popular Slideshows & Tools on WebMD

disciplining a boy
Types, symptoms, causes.
Remember your finger
Are You Getting More Forgetful?
fruit drinks
Eat these to think better.
No gym workout
Moves to help control blood sugar.
acupuncture needle on shoulder
10 tips to look and feel good.
Close up of eye
12 reasons you're distracted.
birth control pills
Which kind is right for you?
embarrassed woman
Do you feel guilty after eating?
Epinephrine Injection using Auto-Injector Syringe
Life-threatening triggers.
woman biting a big ice cube
Habits that wreck your teeth.
pacemaker next to xray
Treatment options.
caregiver with parent
10 tips for daily life.

Pollen counts, treatment tips, and more.

It's nothing to sneeze at.

Loading ...

Sending your email...

This feature is temporarily unavailable. Please try again later.


Now check your email account on your mobile phone to download your new app.

Women's Health Newsletter

Find out what women really need.