Forensic scientists are hard at work to take forensic toxicology — the science behind determining cause of death and other matters of interest in crimes — to a new level by using hair to identify people.
A team of researchers at the Lawrence Livermore National Laboratory in California were able to demonstrate that they can name an individual based on unique proteins in hair, Quartz reports.
DNA is currently the highest level of identification in forensics. The combination of gene variations that show up as physical traits are what makes each person unique. This explains why DNA is such a valuable tool in solving crimes.
The problem with DNA, however, is that it breaks down easily when not in living cells. Brad Hart, a researcher on this study and a chemist at Livermore’s forensic science division, says, “When the DNA molecule degrades from light, heat exposure or other environmental conditions, it becomes useless for identification.”
On the other hand, hair is a durable substance. While it does not contain DNA, it does have some of the proteins present in DNA codes. Deon Anex, also a researcher on the study and chemist at Livermore, says,
We’re basically exploiting the link between the protein back to DNA, which allows us to use a lot of the rules that apply to DNA.
Hair is made of proteins, which in turn are made up of amino acids. Proteins require a certain structure to work, but amino acids can sometimes trade with each other without any negative effects. The researchers found that if they could find these small amino acid tradeoffs in a given protein, they could likely also trace those switches back to one mutation in the DNA. So the combination of these different variations in protein structures in one strand of hair can potentially identify individuals in the unique way DNA can.
The researchers examined hair from 66 men and women of European ancestry, five African-Americans, five Kenyans and six sets of remains dating back to the 1700s and 1800s. They found 185 separate amino acid patterns or markers. As they continue with their research, they expect to find nearly 1,000 more markers so that identification is as precise as possible.
Anex says that as of now, the process requires a lock of hair so that they can identify someone, but they’re working to develop a method where a single strand will suffice. It might take as long as ten years before hair will be as effective a DNA in a court of law, but when refined, the technique is expected to be immediately useful in crime.
