WalkSnap via Twitter asked:
If you incubated bacteria on a mobile phone touch screen, what bacteria would you find, and could you tell the areas that are touched most?
Helen - I don't have a touch screen. I've got an old fashioned one with buttons, but I imagine the same thing would count with buttons as well as touch screen.
Ben - I think it probably would.
Helen - I suppose it all comes down to how well you wash your hands after you've been to the bathroom – what kinds of bacteria that pass through our systems end up on our hands and on our phone. Will they survive and live on our phones? That’s the question I suppose. Would they be able to actually form colonies?
Ben - Well bacteria can survive quite a long time actually on various surfaces and we know of around about 1,000 different bacteria species that will live on our skin. I think you probably could tell the key areas that are touched most because you're going to put down more grease on there, you're going to put more skin cells which will act as food, and you're going to put more bacteria on there, so yes, possibly. It could be a very good way to find out what buttons people press most often which is really quite disturbing when you think about it that way...