2. Pour agar in a petri dish. Agar is a gelatinous substance used in cooking that also serves as a growth medium suitable for science experiments. Refrigerate petri dish upside.
3. Rub a sterile swab over the areas of door knobs, mouse of computers, cafeteria tables, and classroom desks to collect bacteria. Use a light touch, but make full contact with the surface.
4. Rub the swab containing sample onto the prepared agar and close the petri dish. Place petri dishes in an out-of-the way spot, out of direct light. It will take three to seven days for growth to appear.
5. Examine petri dishes as growth begins to appear. Bacteria