A buccal swab, also known as buccal smear, is a way to collect DNA from the cells on the inside of a person's cheek. Buccal swabs are a relatively non-invasive way to collect DNA samples for testing. Buccal means cheek or mouth. It is very common in clinical trials and in law enforcement investigations where it can include or exclude individuals as suspects.
^McMichael, Gai L.; Gibson, Catherine S.; O’Callaghan, Michael E.; Goldwater, Paul N.; Dekker, Gustaaf A.; Haan, Eric A.; MacLennan, Alastair H.; South Australian Cerebral Palsy Research Group (Dec 2009). "DNA from Buccal Swabs Suitable for High-Throughput SNP Multiplex Analysis". J Biomol Tech. The National Center for Biotechnology Information, US National Library of Medicine, National Institutes of Health. Research Ethics Committee of the Children, Youth and Women's Health Service. 20 (5): 232–235. PMC2777348. PMID19949693.