DNA fingerprints. The photo shows an X-ray (or autoradiograph) of bands of DNA produced by the technique of electrophoresis in an agarose gel. The pattern of these DNA bands is unique to each individual human being or other animal, and form a kind of genetic identity card". Because some bands are shared by related people, such as a parent & child. DNA fingerprints can be used to prove conclusively whether people are related, for instance in cases of disputed paternity. The technique is also used to identify & convict criminals from blood, hair, sperm or other tissue left at the scene of a crime."