DNA testing...is the most important study in today's world. So how did this DNA finger printing came into existence. Lets see how these finger printing technology helped to solve cases.
Eureka Moment
On September 10, 1984, geneticist Alec Jeffreys, 34, was working in his lab at the University of Leicester, in central England. More precisely, he was in the lab’s darkroom, studying an X-ray that had been soaking in a developing tank over the weekend. The X-ray was the result of a process through which recently discovered DNA sequence anomalies appeared on a sheet of film as rows of black lines interspersed with blank spaces- almost like bar codes. The particular X-ray he was looking at showed DNA “bar codes” from three people: one of his technicians and her mother and father.
Jeffreys had no idea what to expect from the X-ray- he was just inventing the process, hoping to see evidence of change to specific regions of DNA between the parents and their daughter. But after looking at the blurry mess of dark and light spaces for a few moments, he suddenly realized that, completely by accident, he had discovered a way to tell if people were related. “It was an absolute Eureka moment,” he told a reporter in a 2009 interview with The Guardian newspaper. “It was a blinding flash. In five golden minutes, my research career went whizzing off in a completely new direction.”
After the Eureka
What Jeffreys saw in that blurry X-ray: 1) each of the three family members had their own unique “bar code,” 2) all three of the family members’ bar codes related to one another (which makes perfect sense, as each of us gets our DNA as a combination of our parents’ DNA), and 3) the relationships were plainly visible. Jeffreys quickly realized that his findings would have implications regarding paternity. With such technology you could prove with scientific certainty whether someone was- or wasn’t- someone else’s child. Or even whether they were closely related. The technology could also be of use in criminal cases where the perpetrators left blood or other biological evidence behind.
Jeffreys had apparently discovered something extraordinary- but what to do with it? Surely it would take decades for it to have any applications in the real world, he thought. So he simply kept working on what he dubbed his “DNA fingerprint” process, trying to improve it. Meanwhile, he wrote a scientific paper titled “Individual-Specific Fingerprints of Human DNA,” which was published in the scientific journal Nature in July 1985.
Two weeks later, he got a phone call.
Test Case: Paternity test.
The call came from a London lawyer who told Jeffreys she’d read a newspaper article about his “DNA fingerprinting” and wondered if it could be used in an immigration case she was handling. A British-Ghanaian woman’s 13-year-old son had gone to stay with her estranged husband in Ghana for some time, and when he returned, British authorities didn’t believe it was him. They thought the family was trying to sneak someone else- possibly a cousin- into the country on the son’s passport, and they wanted to deport the boy. Could Jeffreys prove that the child was the woman’s son?
Jeffreys agreed to give it a try. He took blood samples from the mother, three of her other children, and the boy in question, and made DNA bar codes for each of them. His conclusion: The boy was definitely the woman’s son. The lawyer presented the evidence to the British Home Office, and even though DNA testing had never been used in a case before, they were convinced. The boy was legally accepted as the woman’s son and allowed to stay in the country. Not only that, British immigration officials said they would allow DNA testing to decide any future cases that had paternity questions. The British Home Office had, perhaps without realizing it, made the brand-new, still not widely understood use of DNA testing a legally legitimate procedure.
AFTERMATH:
News of these events made global headlines. Within a year, DNA fingerprinting- now known as DNA profiling- was being used in the United States, and in just a few more years it was considered a standard part of forensics almost everywhere in the world. And not just to find out whodunnit- but also to determine who-didn’t-dunnit.
Jeffreys is still a professor at the University of Leicester, although he is now known as Sir Alec Jeffreys. He was knighted by Queen Elizabeth II in 1994 for “Services to Science and Technology.” He has received numerous other awards for what turned out to be one of the most momentous scientific discoveries of modern times. And it brought him some well-deserved fame: “Literally every two or three days I get an e-mail,” he said in 2009, “mainly from the States, from school kids saying, ‘I’ve got to do a project on a famous scientist, so I’ve chosen you,’ and I love that. I always respond.”
SOME INTERESTING FACTS:
Eureka Moment
On September 10, 1984, geneticist Alec Jeffreys, 34, was working in his lab at the University of Leicester, in central England. More precisely, he was in the lab’s darkroom, studying an X-ray that had been soaking in a developing tank over the weekend. The X-ray was the result of a process through which recently discovered DNA sequence anomalies appeared on a sheet of film as rows of black lines interspersed with blank spaces- almost like bar codes. The particular X-ray he was looking at showed DNA “bar codes” from three people: one of his technicians and her mother and father.
Jeffreys had no idea what to expect from the X-ray- he was just inventing the process, hoping to see evidence of change to specific regions of DNA between the parents and their daughter. But after looking at the blurry mess of dark and light spaces for a few moments, he suddenly realized that, completely by accident, he had discovered a way to tell if people were related. “It was an absolute Eureka moment,” he told a reporter in a 2009 interview with The Guardian newspaper. “It was a blinding flash. In five golden minutes, my research career went whizzing off in a completely new direction.”
After the Eureka
What Jeffreys saw in that blurry X-ray: 1) each of the three family members had their own unique “bar code,” 2) all three of the family members’ bar codes related to one another (which makes perfect sense, as each of us gets our DNA as a combination of our parents’ DNA), and 3) the relationships were plainly visible. Jeffreys quickly realized that his findings would have implications regarding paternity. With such technology you could prove with scientific certainty whether someone was- or wasn’t- someone else’s child. Or even whether they were closely related. The technology could also be of use in criminal cases where the perpetrators left blood or other biological evidence behind.
Jeffreys had apparently discovered something extraordinary- but what to do with it? Surely it would take decades for it to have any applications in the real world, he thought. So he simply kept working on what he dubbed his “DNA fingerprint” process, trying to improve it. Meanwhile, he wrote a scientific paper titled “Individual-Specific Fingerprints of Human DNA,” which was published in the scientific journal Nature in July 1985.
Two weeks later, he got a phone call.
Test Case: Paternity test.
The call came from a London lawyer who told Jeffreys she’d read a newspaper article about his “DNA fingerprinting” and wondered if it could be used in an immigration case she was handling. A British-Ghanaian woman’s 13-year-old son had gone to stay with her estranged husband in Ghana for some time, and when he returned, British authorities didn’t believe it was him. They thought the family was trying to sneak someone else- possibly a cousin- into the country on the son’s passport, and they wanted to deport the boy. Could Jeffreys prove that the child was the woman’s son?
Jeffreys agreed to give it a try. He took blood samples from the mother, three of her other children, and the boy in question, and made DNA bar codes for each of them. His conclusion: The boy was definitely the woman’s son. The lawyer presented the evidence to the British Home Office, and even though DNA testing had never been used in a case before, they were convinced. The boy was legally accepted as the woman’s son and allowed to stay in the country. Not only that, British immigration officials said they would allow DNA testing to decide any future cases that had paternity questions. The British Home Office had, perhaps without realizing it, made the brand-new, still not widely understood use of DNA testing a legally legitimate procedure.
AFTERMATH:
News of these events made global headlines. Within a year, DNA fingerprinting- now known as DNA profiling- was being used in the United States, and in just a few more years it was considered a standard part of forensics almost everywhere in the world. And not just to find out whodunnit- but also to determine who-didn’t-dunnit.
Jeffreys is still a professor at the University of Leicester, although he is now known as Sir Alec Jeffreys. He was knighted by Queen Elizabeth II in 1994 for “Services to Science and Technology.” He has received numerous other awards for what turned out to be one of the most momentous scientific discoveries of modern times. And it brought him some well-deserved fame: “Literally every two or three days I get an e-mail,” he said in 2009, “mainly from the States, from school kids saying, ‘I’ve got to do a project on a famous scientist, so I’ve chosen you,’ and I love that. I always respond.”
SOME INTERESTING FACTS:
- It May seem elementary to CSI fans, but after his discovery on that fateful Monday morning in 1984, Jeffreys had no idea if the DNA in a bloodstain would be usable in his process. So he did the only thing a good scientist could: “I spent the next two days cutting myself and leaving blood marks around the laboratory. Then we tested those bloodstains.” (It worked, of course.)
- Jeffreys’s original X-rays- the ones mentioned at the start of the story, with the bar codes of the three family members- actually held 11 such codes. The other eight were made from the DNA of animals, including a mouse, a cow, and baboon. And in case you were wondering, DNA testing works the same for animals as it does for humans.
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