Science Buddies: "Ask an Expert"

Hi, I'm in the eighth grade and I am doing a science fair project. I am going to test whether colored light helps the slime mold grow quicker throughout a maze. I have several questions. First, I have received the kit. Is there any specific way I should store it? Next, on your on your website it says that you should microwave the agar. However on the culture kit instructions, it says that the proper way to melt the agar is to put it in hot water. Is either method acceptable? Also, when making the maze you just put a piece of transparency paper with them as printed on it on to the agar, correct? Does this mean that the slime mold will not grow over the paper? Lastly, if I wanted to make the agar plates ahead of time, perhaps a day, how would I store those?
Thank you

Hi Avamaldrich,

Physarum Polycephalum is so fascinating. You must be so excited for this experiment!

As mentioned on the website regarding the storage of your kit..."Upon receipt of kit, break seal on plate culture and store at room temperature away from direct light. For best results, use plate culture within 2–3 days of receipt."

Concerning melting the agar, I would go with the directions from the kit you received because the protocol on science buddies is generic to ensure versatility, but the protocol that comes with your kit is specific to the agar provided in that kit. Also, science buddies may have assumed that the agar you would receive would be 1% ( 1 gram of agar per 100 ml of water), but the agar provided online is 2% (2 grams of agar per 100 ml of water) which might not provide as much moisture as the Physarum would prefer if not diluted. However, if you've already begun using the science buddies method for melting, then I would continue using that method. Just make sure to be consistent with your ways to ensure the most accurate data.

Excellent question! I would assume that the mold would not grow over any dry surface if it had a moist one available instead. The transparency paper is plastic which is definitely not moist so yes the mold shouldn't grow over the paper. It worked in the experiment mentioned as background information https://www.sciencebuddies.org/science- ... background. Try scrolling to the middle of that page to see the diagrams of the maze.

I actually have a perfect link for you concerning storage of agar plates...I used it the first time I stored agar plates too!
http://www.umsl.edu/~microbes/tipsforplates.pdf

Hopefully this information helped! we're really interested in the results of your experiment. Please let us know what you find out.

-Roya

Hi, I contacted somebody earlier this week regarding questions I had on my project, which I am conducting to find whether different colors of light affect the slime mold ability to remember its previous locations in the maze. I have another question: do you add the oatmeal grains to the maze before or after the slime mold grows entirely throughout the maze. I wasn't 100 percent sure after reading the procedure on your website, for the project entitled "Smarter Than Your Average Slime Mold"

Hi Avamaldrich ,

This is a fascinating project.

The directions suggest transferring an actively growing culture to the agar plate, so this would mean that the slime mold should be fed oatmeal prior to transferring to the maze, The actively growing culture will then be able to grow throughout the maze prior to adding the oatmeal to the two places on the maze to test whether or not the organisms can find the shortest distance to the oatmeal.

Donna Hardy

Hi Avamaldrich. You have chosen a very interesting project and have received excellent advice so far. Please keep all questions about your project to a single thread, so that our experts can best help you based on what has already been discussed.

Good luck, and thanks for using Science Buddies!
Deana