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Forensic Scientist’s New Friend: Hand Bacteria

You may have seen episodes of CSI where the bad guys are catch by matching fingerprints. Now, science may be able to match their hand bacteria.


Photo: Paul Vladuchick (Flickr)

Forget fingerprints! Scientists are using hand bacteria to catch bad guys.

When it comes to catching crooks, forensic science has come a long way.

From Fingerprints To Hand Bacteria

Back in the late 1800s, detectives first started using fingerprints to identify criminals. More recently, during the past few decades, DNA has become an important tool for crime scene investigators.

Now, bacteria may have their day. Hand bacteria, that is–as in the unique mix of bacteria that live on a person’s hands.

Bacterial Cells

The human body is teeming with bacteria. In fact, there are more bacterial cells in our bodies than human cells.

Researchers have found that our hands harbor around 150 bacterial species. But the specific variety of bacteria is largely unique to each hand. Only about 13 percent of bacteria found on a given hand is shared with any other hand.

Capturing Hand Bacteria

But can a person’s unique signature of hand bacteria be used to identify them, much like DNA? A handful of experiments say yes.

For example, researchers at the University of Colorado, Boulder took bacteria samples from computer keyboards.

They compared them to hand bacteria samples taken from the computers’ users, and to samples taken from people who’d never used the keyboards. The keyboard samples matched up much better with bacteria from the computer owners’ than they did with bacteria from strangers.

The Future

More studies need to be done to see if hand bacteria really are useful as a forensic tool. But as a complement to DNA and fingerprints, it could prove a reliable way to put away the bad guys.

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