Science Buddies: "Ask an Expert"

I'm having a hard time coming up with an idea to expand my research on last years project. I'm in 8th grade and made it to County, but missed out on state competition.
Last year I studied the effects of various methods used to clean (sanitize) soda cans. I used a clean cloth, bleach solution, UV light, alcohol wipe.
Looking for ideas to expand on this!

Thanks!

Hi,

How did you measure the cleanliness of the soda cans? By swabbing for bacteria? What did you find in your experiment? Answering those questions will help us to help you expand your project. Off the top of my head, though, I would wonder about other surfaces--does the same sanitizing method work best on other items one might want to sanitize, like a kitchen counter? Alternatively, you could look into why the method that worked best worked best, though depending on your results and resources that might be difficult.

I measured the cleanliness of the cans by swabbing each can and recording the amount of bacteria growth in a agar dish. I cleaned the cans using four methods, a clean cloth, alcohol wipe, cloth with bleach solution and placing the cans under a UV light. I expected the UV light to work the best, but my results showed otherwise. Just wiping them with a clean cloth scored higher 3 out of 4 trials.
I'm thinking about possible other surfaces, but also wondered about testing at least three of the four methods on actual bacteria. I've looked for ways to buy petri dishes with a culture growing or grow my own, but not sure.

Thanks!

Interesting results!

The idea of using actual bacteria is a really interesting one, but you would need to be careful in how you did it. Even 'harmless' bacteria can be very dangerous in large quantities, so you would not want to grow large colonies of bacteria on a plate and then 'clean' them--you could make yourself or someone else very sick. What you could do is take some lunchmeat (NOT raw meat, especially chicken) and place it on, say, a clean breadboard or a countertop. Then clean the breadboard/countertop with one of your four methods, then swab the item and culture the bacteria. That way you could control the amount of bacteria on the item, but you would not be exposing yourself to dangerous amounts of bacteria while you cleaned.

Hope this helps!

Hi, I agree, go with whatever bacteria are already there.

Two ideas on how to improve. First, why cans? What makes them interesting? Perhaps you can find another scenario that is more interesting or applied (cutting boards?).

Second, I would be interested to see the differnece between products that claim to be 'antibacterial' and those that don't. I have heard that normal soap is just as good, but haven't tried the test mysef.

Roland

One way to expand on your project might be to try different disinfectants (bleach, alcohol, iodine and other commercial disinfectants) at different concentration, to see at what concentration the disinfectant work best. You can do a graph comparing the concentration of the disinfectant and the colonies count.
Michael

jmm0837 wrote:I measured the cleanliness of the cans by swabbing each can and recording the amount of bacteria growth in a agar dish. I cleaned the cans using four methods, a clean cloth, alcohol wipe, cloth with bleach solution and placing the cans under a UV light. I expected the UV light to work the best, but my results showed otherwise. Just wiping them with a clean cloth scored higher 3 out of 4 trials.
I'm thinking about possible other surfaces, but also wondered about testing at least three of the four methods on actual bacteria. I've looked for ways to buy petri dishes with a culture growing or grow my own, but not sure.

Thanks!

hi im also having trouble finding cheap petri dishes for my project lol!

im still loooking! if you found a site that has em could you tell me plz cuz my project is due on the 3rd.. any help would be awesome thanks..

stanthescienceman;
you can get petri dishes from carolina.com they hav 20 plates for $25.95.

hey thanks for the website... i really needed them for my project..i have a class in school that does nothing but research and science fair for the first semester so that's great!!! can i add u as a friend?

stanthescienceman