Science Buddies: "Ask an Expert"

I have a question, I need to determine the type of bacterias you can find in restroom doors and I don't know how to collect the samples and how long I have to wait before I can actually look a them in the microscope. So, do you have any idea of how I can do it? I also have to compare what I see with some pictures of bacterias, how do I do that?

Thank you,
OTorres

A good place to start is the science fair project guide:
https://www.sciencebuddies.org/science- ... ndex.shtml
Look under "Microbiology" and you'll find several useful links. Essentially you'll want to get some agar plates, streak the bacteria on, and wait for it to grow. How long this takes depends on the temperature and the bacteria--many will grow up overnight at 37 degrees celsius; at room temperature you'll have to wait a few days.
Then, check out this page for some info on preparing slides: http://www.ruf.rice.edu/~bioslabs/bios318/staining.htm
There are many guides to identifying bacteria. Some observations that will help you are colony (spot on the plate) color, size, and shape, and what they look like under the microscope. Depending on your resources, you can also stain the cells and do other tests. Bacteria come in three basic shapes--have a look around the internet and see if you can find out what they are.
Good luck.

When you mention that you would like to take pictures of the bacteria, do u mean pictures at a microscopic level or pictures of groups of bacteria? I think the only way to take pictures of bacteria at a microscopic level would be to use an electron microscope; however, those microscopes are really expensive and big. Taking pictures of clumps of bacteria should be no problem though, once the bacteria starts becoming visible on the agar plates.

Some light microscopes have cameras attached; alternatively, you could simply draw what you see in the microscope.