Students use microscopes to observe 3 species of helpful bacteria. This lab sheet shows students how to create a lab report by having them fill in certain parts. It can be modified to allow students to provide more of the information (for example, have them write out the procedure or do the research on the types of bacteria used).
Two of the species of bacteria used, Nostoc and Anabeana can be purchased from a biological supply company, the other, L. acidophilus, is found in yogurt. To prepare the yogurt culture, simply mix a small amount of yogurt with water. I sometimes found it helpful to add a dye to the mixture to make observing the bacteria easier.
I got the samples from a biological supply company (like Carolina). They come in a water solution so all you need to do is put a drop on a slide with a cover slip. For the yogurt culture I mixed a small amount of plain yogurt with water and put on a slide with a coverslip. We use microscopes that have powers of 4x, 10x and 40x.