fingerprinting

Act of taking an impression of a person's fingerprint. Because each person's fingerprints are unique, fingerprinting is used as a method of identification, especially in police investigations. The standard method of fingerprint classification was developed by Sir Francis Galton and Sir Edward Henry; their system was officially introduced at Scotland Yard in 1901. The U.S. Federal Bureau of Investigation maintains a fingerprint file on more than 250 million people; fingerprints retrieved from a crime scene may be compared with those on file to identify suspects. DNA analysis, which examines regions of DNA unique to each person, is sometimes called DNA fingerprinting.

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Method developed by the British geneticist Alec Jeffreys (born 1950) in 1984 for isolating and making images of sequences of DNA. The procedure consists of obtaining a sample of cells containing DNA (e.g., from skin, blood, or hair), extracting the DNA, and purifying it. The DNA is then cut by enzymes, and the resulting fragments of varying lengths undergo procedures that permit them to be analyzed. The pattern of fragments is unique for each individual. DNA fingerprinting is used to help solve crimes and determine paternity; it is also used to locate gene segments that cause genetic diseases, to map the genetic material of humans (see Human Genome Project), to engineer drought-resistant plants (see genetic engineering), and to produce biological drugs from genetically altered cells.

Learn more about DNA fingerprinting with a free trial on Britannica.com.