Forensic hair analysis has lost some credibility in recent years as the FBI has acknowledged that their microscopic hair comparison unit overestimated their accuracy in matching forensic hair samples for many years. However, recent research in hair proteins may bring hair analysis to the forefront of forensic analysis, as an identifier more unique than DNA sequencing.
The problem with using DNA in forensic study is that it breaks down pretty quickly when it’s not inside living cells. Small amounts of DNA survive inside hair, hidden in mitochondria. It’s not as complete as DNA from a living cell nucleus. In contrast, hair proteins are more stable and abundant than DNA, and researchers are finding many variations that may be unique to the individual.
A study from Lawrence Livermore National Laboratory, USA, published in September 2016, analyzed hair from 76 men and women, as well as 6 samples from remains up to 250 years old. So far they have found 185 distinct patterns of amino acids, called markers, that could be used to identify an individual’s genetic identity. Upon comparing the protein analysis to DNA samples from the subjects, they were able to match the hair to the individual over 98% of the time. The researchers found protein analysis to have a specificity of 1 in 100,000, as compared to 1 in 10,000 with mitochondrial DNA.
Protein based identification could become another great tool for crime scene investigators, as well as archeologists. Research is expanding into proteins from other tissues such as skin, teeth and bones. Eventually proteins from the hair and body may be used to identify individuals in a court of law, alongside or in favor of DNA.
Humans may be uniquely identified by the proteins in their hair
PLOS. "Humans may be uniquely identified by the proteins in their hair: Protein identification technique may be used in forensics, archaeology." ScienceDaily, September 7, 2016.
Proteins In Your Hair Could Uniquely Identify You At A Crime Scene
By Knvul Sheikh, Popular Science, September 9, 2016
Report: FBI overstated hair matches in trials
Marisol Bello , USA TODAY, April 19, 2015
No comments:
Post a Comment