DNA fingerprinting is a test to identify
and evaluate the genetic information—called
DNA (deoxyribonucleic acid)—in a person's
DNA samples can:
Determine who a person's parents are (establish
paternity and maternity). Tissue samples from two people can also be compared to determine
how likely they are to be blood relatives.
Determine whether a
suspect was present at a crime scene, by comparing DNA from the scene to the
DNA of the suspect.
Positively identify a body. Bone and hair
samples can be used to identify a badly decomposed body.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
Sample size. The possibility of having
inaccurate test results increases if a very small sample of DNA is available
for testing. The chance that the DNA will be mixed up with some other DNA is
also higher with a smaller sample.
Having had a blood transfusion within the past 3
Decay of the tissue sample.
What To Think About
Because DNA fingerprinting has been used to
identify bodies, such as military personnel killed in action or crime victims,
DNA databases (much like fingerprint databases) have been developed. DNA
fingerprinting is more accurate than traditional fingerprints, dental records,
blood type, or ID tags for this purpose.
Although home paternity test kits are available, they are not as
accurate as DNA fingerprinting, and the results cannot be used in a court of
law. If you are thinking about using of one of these kits, talk with your
Other tests that can help determine the likelihood of two
people being related or that can detect inherited diseases include karyotyping
and genetic testing. For more information, see the topics
Karyotype Test and
Other Works Consulted
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.