Petri dish experiment shows off just how many bacteria live on your phone

Mobile phones can harbour disease - and a set of Petri dish ‘prints’ of the bacteria lurking on the surface of the average smartphone show exactly how dirty most mobiles are.

The ‘prints’ were created by University of Surrey students, as part of an annual project about bacteria in everyday life.

Phones carry bacteria from their owner - and even from other people, or from soil if you put them on the ground.

Dr Simon Park, behind the project, suggests that nose-pickers who go on to text message will create bacteria colonies on their phones.

As iPhones and other smartphones have become popular, patterns have started emerging in the annual crop of bacteria dishes - for instance, bacteria tend to ‘cluster’ around the Home button on iPhones.

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Phones could carry bacteria you’ve picked up from other people – with different blotches in the dishes showing different growths in the annual University of Surrey project.

Dr Simon Park, the lecturer behind it says that phones store a record of our personal contacts – ie people we touch – as surely as they store our phone contacts.

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Dr Park, Senior Lecturer in Molecular Biology, said: ‘As part of a course called Practical and Biomedical Bacteriology, an undergraduate module that I run, I get the students to imprint their mobile phones onto bacteriological growth Petri dishes so that we might determine what they might carry.

‘It’s unusual but very effective way of engaging our students with the often overlooked microbiology of everyday life.’

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‘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.’