Alec Jeffreys, a geneticist working at the University of Leicester, never intended to invent genetic fingerprinting. But at 9.05am on the morning of 10th September 1984, that’s exactly what he did.

In the latest episode of Genetics Unzipped, Kat Arney looks back over the unlikely discovery of DNA fingerprinting and the man behind it.

In 1977 – the year that Fred Sanger invented his eponymous DNA sequencing technique – Jeffreys arrived in Leicester, complete with suitably 70s hair and beard, taking up the position of lecturer in the Department of Genetics.

Rather than focusing on investigating how information was stored within the sequence of DNA, he decided to take a different tack, instead looking at how DNA varied between people, so he could trace how different versions of genes linked to traits and diseases were inherited down the generations.

He and his colleagues started a systematic survey of one section of the human genome, trying to spot how it differed between individuals. But he soon realised this task was a lot tougher than he first imagined.

The variations between people were very hard to detect with the tools at the time, and not particularly informative. Surely, he figured, there must be other regions in the genome that were more variable – and easier to work on.

This quest led him to develop restriction fragment length polymorphism (RFLP) mapping – the first technique capable of generating a unique genetic ‘barcode’ for any living thing.

It’s now 35 years since Jeffreys and his team published their discovery in the journal Nature. Within a few months of publication, they were deluged with requests from people desperate to use this new technique to solve their problems.

From immigration disputes and paternity suits to horrific murders and wildlife crime, genetic fingerprinting soon became a mainstay of forensic science and family justice. We take a closer look at two of the first crucial cases.

First, we discover how genetic fingerprinting of a family solved the Ghana Immigration case – a tribunal involving Andrew, a 13-year-old boy detained upon his return from a family holiday. We also explore how DNA profiling (along with some smart policing) helped to catch the brutal murders of two Leicestershire schoolgirls, exonerating an innocent suspect in the process.

Listen to the full episode now at GeneticsUnzipped.com

Genetics Unzipped is the podcast from the UK Genetics Society, presented by award-winning science communicator and biologist Kat Arney and produced by First Create the Media.  Follow Kat on Twitter @Kat_Arney, Genetics Unzipped @geneticsunzip, and the Genetics Society at @GenSocUK

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