Skin cells and their DNADNA, or Deoxyribonucleic Acid, is the genetic material found in cells, composed of a double helix structure. It serves as the genetic blueprint for all living organisms. varies between individuals, but new data shows that some groups of people have higher variability in their cell deposits. The South Australian forensic science researchers are building a suite of new insights into crime scene investigation — including the difference between high, intermediate and low skin ‘shedders’ that will help understanding of trace or ‘touch DNA’.
The latest research, ‘DNA deposited in whole thumbprints’ (just published in Forensic ScienceForensic science is a method that applies a scientific process and technical approaches to study traces rooted in criminal activity or a litigious civil or administrative matter. Forensic science, also known as criminalistics, is a field... International: Genetics), further studies inter-variation of DNA shedding obtained from experiments on samples gathered from 10 different people and 30 of their thumbprints.“The first challenge at a scene is finding touch DNA, which is why we have developed an accurate special aerosol fluorescent dye ‘marker’,” says Professor Adrian Linacre, who leads Flinders University’s forensic DNA technology research group.“A further challenge is evaluating the value of the evidence, and that’s where shedders are a factor.“DataInformation in analog or digital form that can be transmitted or processed. like this new study allows a growing understanding of differences in DNA ‘shedding’ between people, and why we might find traces of people’s DNA a long time after an event.”Flinders University PhD candidate Todd Kaesler says: “We have found that some people have higher intra-variability, indicating that these individuals will not always reliably pass on similar amounts of cellular material and DNA. This is individual-dependent.“Any new data on cell deposition goes to strengthen our understanding of how cells are deposited and why some are found well after a criminal event.”
The study used a nucleic acid binding dye that shows the number of cells deposited when a person touches an object.
“Our work leads to more reliable touch DNA collection methods, which can be key in forensic casework,” says Professor Linacre.
“We look forward to producing more accurate methods and informative research to help forensic scientists to fulfil their roles in a challenging environment.”
Journal Reference: Todd Kaesler, K. Paul Kirkbride, Adrian Linacre. DNA deposited in whole thumbprints: A reproducibility study. Forensic Science International: Genetics, 2022; 58: 102683 DOI: 10.1016/j.fsigen.2022.102683
