Researchers from Flinders University in Australia are looking for a way to measure DNA shedding, which could ultimately have an impact on criminal investigations.
Currently, there is no reliable way to measure and collect the natural shedding of skin and other cells for individuals considered low shedders to compare with the DNA gathered from crime scenes.
However, the researchers have tested a new novel forensic technique on 100 volunteers to confirm how individuals shed varying levels of touch DNA, but do so consistently.
This could have a big impact on criminal investigations as police could reliably collect DNA from crime scenes and compare what was found to what is shed by the individual once a suspect is identified.
The robust, inexpensive, and simple test can show consistent levels of DNA shedding in individuals as a way to build a DNA profile of suspects and test the possible time spent at a crime scene.
"Our latest study also shows that males are more prolific at shedding in general, depositing more cells per square millimeter than females," Professor Adrian Linacre, from the College of Science and Engineering, said in a statement. "Also, there was no difference in the deposition of cells between right and left thumbs, so it doesn't matter if an item is held in someone's right or left hand."
The results show individuals can vary from very low DNA shedding to very high DNA shedding.
In the study, 98 of the 100 donors gave consistent and reproducible cell number depositions. This proved that individuals will shed the same number of cells regardless of when the samples are taken.
"Depending on what type of 'shedder' a person is, confirmation of their shedder status can guide investigators as to the propensity of an individual to pass on their DNA to an item via touch contact with the hand,” Linacre said. "This information can be used in a likelihood ratio to evaluate the probability of finding a person's DNA on an item.”
The pursuit of this breakthrough began three years ago with an initial pilot study.
The investigators indicated they will continue to study this process in an effort to fine tune the test and better utilize the techniques for real world applications.
The study, “Shedding more light on shedders,” was published online in Forensic Science International: Genetics.