Science Buddies: "Ask an Expert"

leemays wrote:I'm not sure what kind of "items" you want to collect germs from. You could try using a cotton swab (like a Qtip) and rubbing it on the item and then rubbing the swab on the dish. Another tool you could use is a sterile metal loop. A common technique for spreading (called the streak plate technique) is to divide the dish into four quarters. Take your initial sample and rub it one quarter of the dish. Then take a clean swab (or heat your loop to kill the bacteria already on it) and run it over the section you just used, then smear that over the next quarter of the plate. Repeat this until all four quarters have been filled. The purpose of this is to dilute the bacteria so you can look at the different colonies.

For more info about how to do a streak plate culture, do a google search using "streak plate culture." Here's one site I found:

http://www.floyd.edu/subwebs/mcdade/lab ... LATION.htm

Good luck!