The specimen for DNA testing is collected through rubbing the cheeks inside the mouth to obtain the mouth lining scrapings. Only long swabs similar to Q-tips are used for the collection of the specimen. The tests used for identifying DNA in blood samples are exactly the same tests used for the identification of DNA with mouth lining scrapings, making one advantage of using buccal cells over blood samples is the easy collection of the specimen. Furthermore, no fasting is required for the purpose of collecting the specimen unlike with the collection of blood specimens.
Aside from the ease of collection, this type of DNA specimen collection is non-invasive and painless. By stroking the lining of the inner cheek with the use of cotton swabs, epithelial cells are collected and these cells contain the DNA required for parentage testing.
The PCR DNA tests are also relatively faster. The results are normally available within three to nine days.
Another advantage of using mouth lining scrapings is that these buccal cells require no refrigeration or preservatives. Unlike other types of specimens, the scrapings do not require immediate shipping to the laboratory. The buccal swab DNA specimens are not affected by bacteria or other products in the mouth such as lipstick, chewing gum, or toothpaste. In fact, the specimens are still useful even after years of storage.
The last advantage of using mouth lining scraping is that the method only requires a small of amount of specimen to perform the test. The subjects, including the mother, father, and child, can provide the specimens and these will adequate to perform the paternity testing.