Microbiology: Bacteria Growth On Toothbrushes: At various distances from Toilet

	Project title: Microbiology: Bacteria Growth On Toothbrushes: At various distances from Toilet
Difficulty level:	Middle school
Main link:	None

Hypothesis:

The toothbrush placed at the farthest distance from the toilet will have the least amount of bacteria growth.

Materials:

a. (11) Toothbrushes
b. (11) Petri Dishes Filled with Agar
c. (11) Sterile Swabs
d. Mouthwash
e. Microscope
f. Toothbrush Cap
g. Sterile Gloves
h. (1) Marker
i. (1) Roll of Tape
j. Distilled Water
k. (1) 100ml Beaker beakers
l. Spray bottle
m. Pen
n. Notebook
o. 110ml of Saline Solution
p. Incubator

The Procedure:

1. Put on Sterile Gloves.
2. Fill a 100ml beaker with distilled water.
3. Submerge (10) toothbrushes in distilled water.
a. Cover (1) toothbrush immediately with sterilized toothbrush cover.
b. Place one toothbrush immediately in mouthwash.
c. Tape one toothbrush on counter directly next to sink (in the classroom bathroom).
d. Tape one toothbrush directly next on the toilet.
e. Tape one toothbrush directly next to the door handle (on the inside of the bathroom).
f. Leave toothbrush submerged in distilled water.
g. Place one on the outside of the bathroom door.
h. Place one toothbrush on the wall directly above the toilet at a height of 1 foot above.
i. Place one toothbrush on the wall directly above the toilet at a height of 3 feet above.
j. Place one toothbrush in a sealed plastic bag.
4. Spray (10) toothbrushes once a day with distilled water.
5. After 2 weeks (14 days) remove labeled toothbrushes from their locations.
6. Fill a 100ml Beaker with 10ml of Saline Solution.
7. Dip one by one each tooth brush in the 10ml of saline solution .
8. Stir toothbrush for 30 seconds.
9. Immediately dip swab in solution and stir for 30 seconds.
10. Wipe specimen in a zig-zag shape on a the agar in the matching labeled Petri dish .
11. Repeat steps (6) through (10) for each toothbrush.
12. Use one toothbrush freshly out of packaging as the control and perform steps (6)through (10).
13. Incubate labeled Petri dishes for a total of 5 days.
14. View agar and growing bacteria once a day with a microscope.
15. Journal observations each time.
16. After 5 days determine which location fostered the greatest amount of bacteria, and the most variations.