Science Buddies: "Ask an Expert"

During the experiment Waste Not, Want Not: Use a Microbial Fuel Cell to Create Electricity from Waste, I was making the salt bridges and had finished with it and put it in the fridge. However, when I came back the next day, I found that the mixture of the boiled water, agar, and salt had turned into a jelly-like substance in the tube that I had poured it into. Is this supposed to happen or have I done something wrong?
Thanks,
Kabir

Hi Kabir -

It sounds like what you observed was correct. The salt bridge is a 3% agar solution; when set it should be firmer than jell-o but not solid.

Amy
Science Buddies