Just an anecdote but in college I had a chemistry professor who had the absolute filthiest keyboard I have ever seen. It was famous throughout the university be

Just an anecdote but in college I had a chemistry professor who had the absolute filthiest keyboard I have ever seen. It was famous throughout the university because it easily had 1.5mm of grime on every single key. I asked him about it once (I assume others did too) and he said that every year the first year biology students swab his keyboard to grow bacteria in Petri dishes as a part of their curriculum. While those Petri dishes with swabs from other place grow like crazy, nothing ever grows from his keyboard.