March 16, 2010

Hand Bacteria Could Help Forensic Scientists

A new study has revealed that the existence of "personal" hand bacteria, as unique as a person's fingerprints and DNA, could become the latest weapon for forensics experts in their attempts to solve crimes and identify victims.

According to a press release, the researchers at the University of Colorado at Boulder who conducted the study "swabbed bacterial DNA from individual keys on three personal computers and matched them up to bacteria on the fingertips of keyboard owners, comparing the results to swabs taken from other keyboards never touched by the subjects. The bacterial DNA from the keys matched much more closely to bacteria of keyboard owners than to bacterial samples taken from random fingertips and from other keyboards."

The results, published in the March 15 issue of Proceedings of the National Academy of Sciences, show that "each one of us leaves a unique trail of bugs behind as we travel through our daily lives," claims Noah Fierer, assistant professor in the university's ecology and evolutionary science department and chief author of the study. "While this project is still in its preliminary stages, we think the technique could eventually become a valuable new item in the toolbox of forensic scientists."

Fierer and his research team state that the technique is currently between 70 and 90-percent accurate, but note that they expect the accuracy rate to increase as better, more precise technology becomes available to forensic laboratories.

A previous study by Fierer showed that the average human hand is home to approximately 150 different species of bacteria, and that "only 13 percent of bacteria species found on a single hand were shared by any two people," according to the CU-Bolder media release.

The study was funded by the National Science Foundation, the National Institutes of Health, the Crohn's and Colitis Foundation of America and the Howard Hughes Medical Institute.


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