Buccal smear

Definition

A buccal (pronounced "buckle") smear is the painless removal of a sample of cells from the inside of your mouth (cheek) for study.

Alternative Names

Sex chromatin test; Buccal swab

How the Test is Performed

The health care provider will gently scrape the inside of the cheek with a small spatula to collect cells for testing. Sometimes, you can do this yourself.

How to Prepare for the Test

Follow the collection instructions as directed by your provider.

How the Test will Feel

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

Why the Test is Performed

This test is done to get cells for chromosome or DNA analysis, most often for genetic testing.

This test may also help establish sexual identity. When the test is used in this way, it's called the sex chromatin test.

Risks

There are no risks with this test.

Gallery

Buccal smear - illustration — A buccal smear is a test where cells are taken from the cheek. Cells are collected by scraping the cheek with a cotton swab. The cells can be used for genetic testing, as well as evaluated for the presence of Barr bodies (a mass seen in a normal female sex chromosome). When used for that purpose, the buccal smear test can confirm whether the patient is a male or female.

References

Chernecky CC, Berger BJ. Barr body analysis buccal smear for staining sex chromatin mass - diagnostic. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:186-187.

Last reviewed May 2, 2021 by Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team..

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