DNA fingerprint. View of an autoradiogram (X-ray) sheet showing DNA (deoxyribonucleic acid) sequences forming a DNA fingerprint. DNA is the molecule found in all cells which contains the genetic hereditary material. Here the DNA has been sequenced into rows of irregularly spaced black bands. The bands represent the positioning of the four base pairs in the DNA molecule which make up the genetic code in the form of genes. The banding pattern was obtained by fragmenting the DNA with enzymes. A DNA sample can be taken from blood or other body tissues. A DNA fingerprint is unique to every person. It can be used to identify genes of the parents of a child, or of criminals.