DNA fingerprinting is a widely used process, which has progressed greatly in the last couple of decades, especially with advances in DNA sequencing. DNA analysis is conducted to determine genetic ancestry, kinship, disease risks, and drug abuse. The main objective of DNA fingerprinting is to determine the exact sequence of genetic material from an individual or a group of individuals and to provide a genetic identifier or identifier of an individual or an entire group of individuals.
Furthermore, DNA fingerprinting can be used to estimate the ancestry and nationality of a person, such as where they may be from. DNA fingerprinting has also been used to match people with their relatives for the purpose of locating children who were abducted or misidentified after a murder. Fingerprinting can also be used to match DNA samples from different people, to see if they are related or are unrelated to each other. The vast majority of people who submit DNA samples to a police laboratory are convicted criminals, and the DNA testing in those cases can help police catch the suspect or lead to the discovery of a crime. People with lighter skin often have a unique fingerprint pattern on their skin, which is part of the DNA of their skin cells.
DNA Fingerprinting History
The technique was developed in 1984 by British geneticist Alec Jeffreys after he noticed that certain sequences of highly variable DNA (known as minisatellites), which do not contribute to the functions of genes, are repeated within genes. Jeffreys recognized that each individual has a unique pattern of minisatellites (the only exceptions being multiple Alternative Tools).
Moreover, DNA fingerprinting was first introduced to the forensic science community in the United States by FBI geneticist James R. Fetzer in 1988; and it was adopted by the European Union in 1998, with the approval of the United Kingdom’s Home Office. In 2003, the International Association of Chiefs of Police awarded Jeffreys the Truman Capote Award for Creative Excellence for “a groundbreaking and revolutionary technique that has led to the identification of nearly 4,000 criminals in the US alone.” The technique is now routinely used in forensic identification, specifically by the FBI. According to the FBI, DNA fingerprinting has the potential to be a game-changer in forensic science.
The use of genomic DNA in forensic science is an evolution of forensic genetics that began in the 1990s and early 2000s. During this time, the development of sequencing methods allowed the analysis of different species of the organism (e.g., sheep, humans, horses, chickens, etc.), as well as those in a limited range (e.g., plants, fish, and reptiles). Forensic geneticists have also begun using advanced sequencing methods to identify unidentified human remains.
How Does DNA Fingerprinting Work?
DNA fingerprinting is the method by which a person’s genetic information can be identified and compared with that of other people using a DNA test. The DNA fingerprinting test works by matching the minisatellites in the DNA sample to the minisatellites in the “match group” or reference DNA or biological material from a tissue taken from the subject. If the minisatellites do not match, the sample is removed from the testing process and a new DNA sample is prepared. The new sample will contain the minisatellites that match the DNA found in the reference DNA sample.
The details of the technique are fairly complicated, but it basically works by taking a tiny sample of a DNA sample (usually a strand of RNA or a small smidgen of DNA), analyzing it with a variety of highly sensitive techniques, and identifying which of the minisatellites are unique in every individual. This is important because the minisatellites are directly related to biological functions, such as the sequence of amino acids that make up proteins and the chemical code that underlies genetic sequences. By the late 1990s, the technique was in wide use, and a vast number of police departments were using it to help solve old cases.
The enzyme ribonuclease A, also known as RNase A, starts slicing a minisatellite into pieces (smaller pieces are called peptides), which are broken down into individual strands of DNA, which are then separated from other strands. Jeffreys decided to combine the process of RNA digestion with that of restriction endonuclease to improve the accuracy of identification. Nowadays, DNA fingerprinting is used to identify and convict individuals (both living and deceased) who have committed a crime. As such, DNA fingerprinting is an important tool in criminal investigations, even though it is not the only forensic technique that can do so.
Who Can Be Fingerprinted?
From this discovery, and other breakthroughs in molecular biologies, such as DNA sequencing and its analysis, the capability to use DNA fingerprints as forensic tools has made DNA fingerprinting possible. In the process, what is known as the genetic fingerprint is created, and can be used to identify, or exclude, individuals from being contributors to a crime scene. In the 1990s, DNA fingerprinting became one of the most important forensic procedures used to solve and prevent crimes. DNA fingerprinting is considered a powerful tool for individuals seeking justice, especially those suffering from a mental disorder. In criminal investigations, DNA identification plays a crucial role, as it allows law enforcement to determine the identities of the perpetrators involved in a crime.
When we think about DNA fingerprinting, the best term to describe it is simply “DNA analysis.” It is an analysis of the physical makeup of a sample of human DNA that is matched to an in-frame sequence of reference DNA or a prediction of the in-frame sequence. This analysis may be conducted by a lab using whole or partial DNA samples, but may also be used to identify people who have disappeared, such as unidentified remains. In short, DNA fingerprinting can be used to determine the identity of an individual who has been arrested, to confirm a result in court, to solve cold cases, to help a criminal attorney find a suspect DNA profile in a military crime database, or even for a simple genetic ancestry test.