DNA fingerprinting. Conceptual image of autoradio- grams of DNA (deoxyribonucleic acid) sequences peeling back to reveal real fingerprints. The four columns of irregularly spaced bands on each autoradiogram represent a genetic sequence or genetic fingerprint, which, like a real fingerprint, is unique to every individual. A DNA sample can be taken from body tissues or body fluids such as blood. The DNA is then fragmented with enzymes and separated to form the banding pattern. The bands represent the positioning of the four nucleotide bases that form DNA's genetic code. Genetic fingerprinting is used in criminal investigations and to determine paternity.