There's a long held myth that urine is sterile: that you can use it to treat jellyfish stings, sterilise a wound or, hell, even drink it in an emergency. But new research suggests it may not be quite as pure as you thought.
In fact, the idea that it is sterile stems from the fact that urine samples, when cultured, don't create huge plumes of bacteria. Thing is, that doesn't mean that it's sterile; the benchmark for a bacterial urine test is 100,000 colonies in a single millilitre of urine. Less than that, and is counted as clean, which... err, isn't quite true. Allow Sci Show to explain why. [SciShow]