As DNA is unique to each individual, DNA profiling is commonly used for identification both in archaeology and in forensic science. DNA can however be degraded by chemical and environmental processes. This limits its usefulness over time. Protein is more stable than DNA and it is possible that there are protein variations that are unique to the individual. A team led by Glendon Parker, would like to know if the protein found in human hair could possibly be used as a tool for identifying individuals in archaeology and forensic scenarios.
By examining bio-archeological hair samples from six individuals that were up to 250 years old, the scientists were able to show just how robust these proteins are. Analyses of hair samples from 76 living humans of African and European American descent, along with the six old samples produced a sum of 185 hair protein markers to date. The team estimates that this is sufficient to provide a unique pattern for a single individual from within a population of one million.
The aim of the team is to identify a core set of around a hundred protein markers. This would be sufficient to use a single hair to distinguish an individual from among the entire world’s population.
Archaeologists and law enforcement authorities performing crime scene investigations could in future use protein as another tool by utilizing this new identification technique. LLNL chemist Brad Hart, the director of the Lab’s Forensic Science Center and co-author, notes that we are in a place with protein-based identification that is comparable to where DNA profiling was during the initial days of its advance. He believes this method will change the face of forensics, but cautions that while much progress has been made toward proving it, this new technique will only be able to reach its full potential once a number of other steps have been made.
Study has been published in the journal PLoS ONE.