It became possible to identify a person by a hair from any part of the body

American biologists and forensic scientists have made a breakthrough in forensic science. They developed a method for identifying a person by hair from an arbitrary part of the body. The test is not tied to DNA - contrary to popular belief, hair is only suitable for such an analysis in exceptional cases. Instead, they focused on amino acid markers for the proteins that make up hair.

The idea was prompted by nature itself - as a separate object, the hairs are fragile, and DNA can only be obtained from a certain part. Everything else is filled with the fibrous protein keratin, of which there is more than enough, which provided a vast base for research. Using mass spectrometry, scientists have learned to isolate and analyze amino acids in hair proteins, which have become a kind of marker, a personal identifier of the organism on which they grew up.

Keratin in hair lasts up to 250 years under suitable conditions, making it a convenient evidence. Back in 2016, an appropriate identification method appeared, but forensic scientists rejected it, as it was tied to the hair from a person's head. And in practice, hair from the hands and especially the pubis are more often found - the most important evidence in rape. Over the years, a team of chemists led by Fanny Chu, a PhD student at Michigan State University, has proven that similar markers can be found in any hair in the human body.

In the course of the study, methods for statistical comparison of the amino acid trace were developed, which made it possible to immediately indicate where the hair sample was taken from - from the head, arms or pubis. The accuracy of identification has increased to a level where one in 10 million suspects can be identified. And for this, a hair only 2-3 cm long is enough - that's why the method is called breakthrough.