Why Are Mouth Lining Scrapings Used for DNA Analysis?

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Scientists prefer to use mouth lining scrapings for DNA analysis today because of a number of advantages. There are disadvantages too with this routine of using buccal swabs as the DNA specimen of choice. Why are mouth lining scrapings used for DNA analysis? Find out more in this piece of information.

The Buccal Swab Method

The polymerase chain reaction, or PCR, method is one of the most frequently employed technique in DNA analysis. The PCR method is more frequently used with the help of a swab to collect epithelial cells or mouth lining scrapings in the inner cheek. Hence, it is also referred to as the buccal swab method.


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.


The only major disadvantage of the PCR test that uses mouth lining scraping is that it looks at DNA location with fewer possible DNA sizes. Hence, a single DNA location does not provide complete information about paternity. Therefore, accuracy and reliability of the results is one of its major drawbacks.

Latest Development

In the recent years, however, there had been advances in the instrumentation and laboratory techniques. The restriction fragment length polymorphism technique which normally uses white blood specimens is now able to use the epithelial cells collected from buccal swab to provide the same results. Because of RFLP analysis provides more accurate results than the PCR tests, this might be one of the best developments in DNA paternity tests.

Why are mouth lining scrapings the preferred specimen for DNA analysis? Because the collection of the specimen is fast, painless, and non-invasive. The method is very easy, requiring only a small amount of specimen. The samples do not also require high maintenance, making it a very practical method. The only disadvantage is the lesser degree of accuracy and reliability. But with the latest advancements in technology, the use of buccal swab is now getting more accurate and reliable. Therefore, it can be generalized that it is a wise choice for scientists to use mouth lining scrapings for DNA tests.