MedlinePlus Medical Encyclopedia: Buccal smear

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Buccal smear

Contents of this page:
Illustrations Alternative names Definition How the test is performed How to prepare for the test	How the test will feel Why the test is performed Normal Values What abnormal results mean What the risks are

Illustrations

Throat anatomy

Buccal smear

Alternative names Return to top

Sex chromatin test

Definition Return to top

A buccal smear is a painless test in which cells are taken from the tongue and evaluated for the presence of Barr bodies (a type of mass seen in normal female sex chromosomes).

How the test is performed Return to top

Cells are collected by scraping the tongue with a spatula. The cells are then placed on a slide and sent to a laboratory for evaluation.

How to prepare for the test Return to top

No preparation is necessary for this test.

How the test will feel Return to top

You will feel a scraping sensation as cells are removed from the tongue.

Why the test is performed Return to top

In the past, this test was used to indicate:

Abnormal sexual development
Ambiguous genitalia
Amenorrhea
Suspected chromosomal abnormalities

Today, a health care provider who suspects any of these abnormalities is most likely to perform a full chromosome analysis (called karyotyping) rather than a buccal smear.

The buccal smear is primarily used in the Olympic Games or other sporting events if the authorities believe a man is trying to compete as a woman.

Normal Values Return to top

The normal result for a female is an indication of the presence of Barr bodies, confirming the gender as female.

What abnormal results mean Return to top

If no Barr bodies appear, the test subject is a male.

What the risks are Return to top

There are no risks associated with the buccal smear.

Update Date: 1/31/2003

Updated by: Douglas R. Stewart, M.D., Division of Medical Genetics, Hospital of the University of Pennsylvania, Philadelphia, PA. Review provided by VeriMed Healthcare Network.

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