Test Overview
DNA fingerprinting is a test to identify and
evaluate the genetic information—called
(deoxyribonucleic acid)—in a person's cells. It is
called a "fingerprint" because it is very unlikely that any 2 people would have
exactly the same DNA information, in the same way that it is very unlikely that
any 2 people would have exactly the same physical fingerprint. The test is used
to determine whether a family relationship exists between two people, to
identify organisms causing a disease, and to solve crimes.
Only a
small sample of cells is needed for DNA fingerprinting. A drop of blood or the
root of a hair contains enough DNA for testing. Semen, hair, or skin scrapings
are often used in criminal investigations. See a picture of
.
A person who has DNA
fingerprinting done voluntarily usually provides a sample of blood taken from a
vein. DNA testing also can be done on cells obtained by a simple mouthwash or a
swab of the cheeks inside the mouth, but these methods are not
recommended.