Test Overview
DNA fingerprinting is a test to identify and evaluate the genetic
information, called
DNA (deoxyribonucleic acid), of a person's cells. It
is called a "fingerprint" because it is very unlikely that any 2 people would
have exactly the same cellular 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 DNA testing in a criminal investigation
.
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.