DNA transfer: Review and implications for casework

DNA transfer: The role of temperature and drying time

“…There have only been a few studies that have focussed on gaining insights into factors affecting such transfer events [1][2][3][4]. A recent review of current knowledge of DNA transfer and implications for casework by Meakin and Jamieson [5] clearly illustrates the need for a better understanding of DNA transfer.…”

Changes in Yield of Contact DNA over Time after a Physical Assault

“…However, with the rise of new technology, DNA samples no longer need to be visible to analyze. "Touch" or "contact" DNA is DNA that is transferred via skin epithelial cells to an object that is handled or touched [6]. According to Edmond Locard's Exchange Principle, when two items come into contact with each other, there will always be an exchange of material.…”

“…Since then, amplifiable DNA has been collected from countless items including the interiors of latex gloves, grips and shafts of tools, drinking glasses, steering wheels, cellular phones, remote controls, and human skin [3,4,6].…”

“…The quantity and quality of DNA profiles recovered from items depend on the shedder status of individuals that deposited the DNA [6,9]. Good DNA shedders might leave behind a full DNA profile after handling an object, whereas poor shedders may leave a partial or no profile at all.…”

“…Lowe et al [1] suggested that determining the shedder status of individuals and the distribution of shedders in the wider population could help increase the understanding of factors that affect the transfer of trace DNA. In addition to shedder status, the type of contact, length of contact, type of substrate, amount of pressure applied, previous hand washing, personal habits, and perspiration also impact trace DNA transfers [6,9]. …”