Monospot Test

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Also known as: Mononucleosis spot test; mononuclear heterophil test; heterophil antibody test; Mono test
Formal name: Heterophil antibody titre
Related tests: Tests for antibodies to Epstein-Barr virus (EBV) antigens, Paul-Bunnell test

At a Glance

Why Get Tested?

To get screened for infectious mononucleosis (glandular fever). 

When to Get Tested?

If you have symptoms of mononucleosis, including fever, sore throat, swollen glands, and fatigue. (The monospot test is not useful to detect EBV in children.)

Sample Required?

A blood sample taken from a vein in your arm

Test Preparation Needed?


The Test Sample

What is being tested?

The Monospot test detects heterophil antibodies. It detects a reaction with horse red blood cells. A similar test, the Paul-Bunnell test, detects a reaction with sheep red blood cells. The antibodies are made in response to an infection by Epstein-Barr virus (EBV). EBV causes infectious mononucleosis (glandular fever), a self-limiting disease.

Mononucleosis is characterised by the presence of atypical white blood cells (atypical lymphocytes) in an infected person. Patients have these symptoms: fever, sore throat, swollen glands, and fatigue. About 70%–80% of patients with infectious mononucleosis produce these heterophil antibodies, which are not specific for EBV infection but are a good predictor of EBV infection.

How is the sample collected for testing?

A blood sample is taken by needle from a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.