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They're Everywhere: Bacteria

Author(s): Nancy Moreno, PhD, and Barbara Tharp, MS.

Session 2: Procedure and Observations

Direct students to collect samples from the areas they have chosen using clean cotton swabs dipped in distilled or boiled water. Students should rub each swab several times over the area to be tested and then gently rub the swab in a zig-zag pattern over the surface of the gel mixture in the bottom of the appropriate petri dish. Instruct students to open the dishes only enough to swab the gel surface. The control dish should be rubbed (inoculated) with a clean, moist swab. 

Tape each group’s petri dishes closed and store the dishes upside down. If possible, have students observe their cultures every day for 1–3 days. After about three days, have students record their detailed observations.

Funded by the following grant(s)

National Institute of Environmental Health Sciences, NIH

National Institute of Environmental Health Sciences, NIH

My Health My World: National Dissemination
Grant Number: 5R25ES009259
The Environment as a Context for Opportunities in Schools
Grant Number: 5R25ES010698, R25ES06932