Surrey students imprinted mobile phones onto Petri dishes to discover the secret life lurking on their handsets.
After three days, the Petri dishes revealed the phones’ grim footprints.
Luckily, most of the bacteria were harmless. But some disease carrying bacteria, such as Staphylococcus aureus (which can cause skin infections), were occasionally found.
Dr Simon Park, Senior Lecturer in Molecular Biology, said: “As part of our undergraduate module Practical and Biomedical Bacteriology, I get students to imprint their mobile phones onto bacteriological growth Petri dishes so that we might determine what they might carry.
“Each phone tells a story. The ecological niche on the body for Staphylococcus aureus is the nostrils, so a furtive pick of the nose, and quick text after, and you end up with this pathogen on your smartphone.”