Buccal smear
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.
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.
How the Test is Performed
Your 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.
References
Roy S. Molecular anatomic pathology: principles, techniques, and application to immunohistologic diagnosis. In: Dabbs DJ, ed. Diagnostic Immunohistochemistry. 6th ed. Philadelphia, PA: Elsevier; 2022:chap 24.
Version Info
Last reviewed on: 4/24/2023
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 C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
