|MadSci Network: Microbiology|
This is certainly something that can be easily done. You are going to need 2 things. First, you need some petri dishes with culture medium so that the bacteria can grow. There is no single medium on which every bacteria will grow, but some good all purpose medium like Nutrient agar will do well and allow many different bacterial species to grow fine. The second thing you will need is something to take your samples. This can be little swatches of cloth or paper disks (filter paper cut into squares or circles), or even Q-tips (cotton swabs) will work well. However whatever you use needs to be sterile. The simplest thing to do is to wrap a bunch in aluminum foil, and sterilize them. If your school has an autoclave, that will work great. If not, you could put them in a pressure cooker for 30 minutes. If you can't do that, put them in an oven at around 300-350 for an hour or so. BE CAREFUL that there is nothing plastic, which will melt and make a mess. Only paper or cloth. NOTE: Some brands of q-tips have wood sticks, some have paper (white), and some have plastic (usually blue but sometimes white). In order to take your samples, carefully remove one swatch or swab without touching the surface you are going to use to collect the bacteria. It would be best to wear disposable plastic medical gloves (you can get these at a drug store). Rub the swab along the test surface then rub it on top of an agar plate. Repeat for each test site. Be sure to do a control where you just rub a swab on the agar plate without touching anything, to see what your background level will be from the air and your hands. This is the experimental design. However just doing the experiment is not enough. You have to design a hypothesis that you are testing and then test it in a controlled way so that you can interpret your results. Otherwise you will just get a bunch of numbers that don't really tell you anything. So come up with your hypothesis first, then decide how to design an experiment that will test your hypothesis and either support it or disprove it. Have fun!
Try the links in the MadSci Library for more information on Microbiology.