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

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.