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The Origins of DNA Fingerprinting

What is the first thing that comes to mind when you think about DNA fingerprinting? Most people will probably link it to forensic investigations, where crime labs use DNA found at crime scenes to identify the perpetrator. Perhaps you know what DNA fingerprinting is because you have watched lawyers in TV shows use DNA fingerprinting results to solve cold cases.

All DNAs of humans are almost the same but there are slight differences. The differences are in the codes called minisatellites or junk DNA. Even though you inherit these minisatellites from the same parents, your genetic fingerprint will still be a little different from your siblings, unless you have an identical twin! This is because every sibling randomly inherits segments of minisatellites from each parent. Therefore, when scientists analyse your DNA to produce a pattern of dark minisatellite fragments, each fragment will match either one of your parents and this pattern is unique to you.

The person behind the ingenious idea to make use of so-called junk DNA was the scientist Sir Alec Jeffrey. Sir Jeffrey was a British geneticist who worked in a small lab at the University of Leicester. It was the year 1984, and Jeffrey was a young scientist who had just been given the freedom to research in his own lab. By this time, junk DNA or “minisatellites”, had already grabbed his attention. He initially used DNA samples from his lab technicians and their immediate relatives. The young geneticist pondered upon the challenge of understanding why all their minisatellite profiles were so different. Then, the ‘eureka ‘moment hit him—he was looking at their genetic fingerprints!

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perpetrator – a person who is guilty of committing something illegal
ingenious – clever, creative
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