Science Buddies: "Ask an Expert"

Hi, I am doing a science project involving the use of agar plates and bacteria. I have zones of inhibition and wish to bring in my agar plates on presentation day. But I don't want the bacteria to keep on growing, because I am afraid that that will change some of my results that I have already recorded. What can I do to make sure that the bacteria (e. coli) does not grow any more, or grows very slowly?

I was thinking of storing it in a refrigerator at 4 degrees Celsius, but im not 100% sure...

Hi,
There are actually a variety of bacteriostatic agents that you might try and use. Check out this link for a list of such agents!

http://en.wikipedia.org/wiki/Bacteriostatic

Refrigeration will also slow down the rate of bacteria growth, although this may not always work. Best of luck!

Instead of bringing the actual agar plates, you might consider taking pictures of the plates along with a ruler so others can see the size of zones of inhibition. Keep in mind that the agar plate only have so much nutrient and eventually the bacteria will start dying.

Michael