A long handshake can spread your DNA to objects you didn’t touch

BALTIMORE — A 10-second handshake could transfer a person’s DNA to an object that the person never touched.
In handshaking experiments, people who never picked up a knife became the major source of DNA on the handle about 7 percent of the time, forensic scientist Cynthia Cale reported February 21 at the annual meeting of the American Academy of Forensic Sciences. That DNA was transferred to the knife when the person’s handshaking partner grasped the handle.