How Reliable Is a DNA Swab Test?

A DNA test examines the genetic material, deoxyribonucleic acid (DNA), that is found inside of all living human — and other — cells. One way of collecting DNA is through the use of a cheek swab, a process in which a sterile cotton swab is used to collect cells from inside the cheek to be used for the test. Since all cells in the same person have the same DNA, a swab test is just as reliable as any other method of DNA testing.

Because DNA comes half from the mother and half from the father, when it is examined in the laboratory, the DNA profile can be matched to both the mother and the father. If a test shows that a child’s DNA does not match one or both of the parents, the child is not biologically related to that parent. There is rarely any question of who the mother of a child might be, but DNA testing is often used to determine the identity of the father. According to laboratory information, a man can be determined to be a person’s father with as much as 99.99% accuracy, but if he is not the father, he can be ruled out with 100% certainty.

The DNA swab test is accepted by courts when making a determination of paternity. There is no difference between the cells inside of the cheek and the blood cells, in terms of DNA content. This makes DNA testing much easier and less invasive than it was in the past, when a blood sample was required in order to perform the testing. A DNA swab test can be done on a newborn infant with no pain or trauma to the child, providing accurate paternity results right from birth.

For parents who have some doubts about a child’s paternity, it is possible to purchase a home version of the DNA swab test and mail it to a laboratory. Collections done at home are not legally binding, but this simple procedure can help in many cases where a man is unsure if a child is really his or the mother knows that more than one man could be the father. Using a DNA swab test in such situations helps to remove doubt and to reassure the father. These tests cost well under $100 US Dollars (USD) as of the spring of 2011, and they are very helpful in resolving paternity disputes. If a paternity test must be done to establish legal paternity, courts will still accept the DNA swab test, but the collection must be done under controlled circumstances to ensure that the right people are being tested.