"COMB SEARCHES" may be on the way to replacing strip searches in criminals' nightmares, thanks to a new technique known as DNA fingerprinting.
The technique, which produces a visual representation of a person's genome, enables the identification of perpetrators from as little as a single hair root, providing they have left some biologic evidence—hair, skin cells, blood, or semen—at the scene of the crime.
DNA fingerprinting was developed by British geneticist Alec Jeffreys, PhD, in 1985. Jeffreys, professor of genetics at the University of Leicester, built upon a discovery, five years earlier, of certain hypervariable regions called minisatellites in unexpressed areas of DNA.
The hypervariability was evidenced in the number of repetitions of certain sequences of base pairs. For example, in a given minisatellite, a certain 32-base pair segment may appear 28 times in one person's DNA, 22 times in another's, and 19 times in a third person's.