Detectives combing crime scenes for clues about 'who dunnit' may soon have a new weapon in their arsenal with which to catch criminals.

Scientists have discovered that unique protein markers in hair could be used alongside DNA profiling to identify humans.

And because hair proteins are more stable than DNA, the technique could be used to identify ancient humans and solve long-forgotten mysteries.

Scientists have discovered that unique protein markers in hair could be used alongside DNA profiling to identify humans. And because hair proteins are more stable than DNA, the technique could be used to identify ancient humans and solve long-forgotten mysteries

DNA profiling is commonly used for identification in forensic science and archaeology because DNA is unique to each individual.

However, it is easily degraded, which limits its usefulness over time.

In a bid to overcome this problem, a team led by Glendon Parker from Lawrence Livermore National Laboratory in California, investigated whether the protein found in human hair could offer another tool for identifying individuals in forensic or archaeology scenarios.

The researchers looked at bioarchaeological hair samples from six individuals that were up to 250 years old, demonstrating the robustness of these proteins found in the hair shaft.

PROTEIN IN HAIR COULD BE BETTER THAN DNA PROFILING The new identification technique using protein could therefore help law enforcement authorities track down criminals from evidence left at a crime scene and enable archaeologists to identify mysterious human remains. 'We are in a very similar place with protein-based identification to where DNA profiling was during the early days of its development,' said co-author and LLNL chemist Brad Hart, the director of the Lab's Forensic Science Centre. 'This method will be a game-changer for forensics and while we've made a lot of progress toward proving it, there are steps to go before this new technique will be able to reach its full potential.' Advertisement

They analysed these samples along with hair samples from 76 living humans of European American and African descent.

The team found a total of 185 hair protein markers, which they believe may be sufficient to provide a unique pattern for an individual that could distinguish that person among a population of one million.

Detectives combing crime scenes for clues about 'who dunnit' may soon have a new weapon in their arsenal with which to catch criminals. The new technique using protein could therefore help law enforcement authorities track down criminals from evidence left at a crime scene

ISN'T HAIR ALREADY USED BY FORENSIC EXPERTS? There is a long history of using hair shafts by forensic experts and anthropologists. Recently hair shafts collected from an extinct Palaeo-Eskimo living around 4,000 years ago and an Australian Aboriginal living 100 years ago were used to obtain complete mitochondrial and nuclear genomes. But, the study explains: 'These are exceptional cases using gram quantities of hair… most hair shafts are a poor source of nuclear DNA,' and using them for other methods is not recommended. Currently, best practice includes sequencing of hair shaft mitochondrial DNA, which is passed down the female line, to identify genetic markers on a single chromosome. 'This method provides identification and biogeographic information, but is less discriminating than STR-typing [part of DNA profiling], requires careful handling and sequencing, and is susceptible to environmental factors,' the authors write. 'Other hair shaft-based forensic methods can be problematic. Microscopic hair comparison, while heavily used historically, does not have the potential for rigorous statistical and scientific analysis,' they continued. The authors of the study, published in the journal Plos One, hope to identify a core set of around a hundred protein markers that would be sufficient to distinguish an individual among the entire world's population using a single hair Advertisement

The authors of the study, published in the journal Plos One, hope to identify a core set of around a hundred protein markers that would be sufficient to distinguish an individual among the entire world's population using a single hair.

The new identification technique using protein could therefore help law enforcement authorities track down criminals from evidence left at a crime scene and enable archaeologists to identify mysterious human remains.

'We are in a very similar place with protein-based identification to where DNA profiling was during the early days of its development,' said co-author and LLNL chemist Brad Hart, the director of the Lab's Forensic Science Centre.