Sex chromatin test; Buccal swab
A buccal (pronounced "buckle") smear is the painless removal of a sample of cells from the inside of your mouth (cheek) for study.
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.
There are no risks with this test.
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 on: 5/2/2021
Reviewed 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.