ABSTRACT
A wad of spit, a spot of blood, a semen stain, or a single hair is all that is necessary to create a DNA “fingerprint.” DNA profiles can be extracted not only from blood or sperm at a crime scene, but also from objects touched by a person’s hands, and from saliva used to lick stamps. From a tiny sample of body tissue, a forensic laboratory can use an autoradiogram to create an image consisting of a cluster of horizontal bands that form a pattern resembling a bar code.
