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.