BOMBING BACTERIA

1
BOMBING BACTERIA

• Scenario
• The custodians at MJHS are trying to create a
  healthier school environment. In order to
  accomplish this task, they need to develop new
  cleaning solutions that control the growth of
  bacteria that live in our classrooms.
• Task
• You have been chosen to be on a task force that
  determines what solutions work best to kill
  bacteria.
• Problem
• In order to create a healthier classroom
  environment what product(s) could you use to
  effectively control the growth of bacteria?

2
What Do You Already Know?

• List some cleaning products

• Which of these cleaning products do you think
  kills germs or bacteria?

3
What Do You Want to Know?

• Our goal is to kill bacteria. What kind of
  information do you need to collect about cleaning
  products to reach this goal?

4
HELPFUL WEBSITES

• www.colgatepalmolive.com
• www.homesolutionsnews.com
• www.mrclean.com
• www.clorox.com/science/
• www.grease.com/

5
Bombing Bacteria Lab

• Purpose/Problem
• In order to create a healthier classroom
  environment what product(s) could you use to
  effectively control the growth of bacteria?
• Hypothesis (remember to use If/Then form)
• Materials
• 2 glass droppers 1 cleaning product
• Wax pencil transparent tape
• 2 petri dishes with sterile nutrient agar

6
Procedure

• Obtain 2 petri dishes containing sterile agar
• Without opening them, use a wax pencil to label
  the bottoms A and B. Write your group name
  beside each letter.
• Wash your hands thoroughly with soap. Collect
  your bacteria sample. Your partner should hold
  open the cover of petri dish A while you run your
  bacteria sample gently across the agar in a
  zigzag motion. Close the petri dish immediately.

7

• Repeat step 3 for dish B.
• Using a glass dropper, transfer 2 drops of
  cleaner to the center of petri dish A. Open the
  cover just long enough to add the cleaner to the
  dish. Record the name of your cleaner in the
  data table.
• Tape down the covers of both petri dishes so that
  they will remain tightly closed. Allow the 2
  dishes to sit upright on your work surface for at
  least 5 minutes. Caution Do not open the petri
  dishes again.

8

• Wash your hands with soap and water.
• Store the petri dishes in a warm, dark place
  where they can remain for at least 3 days.
• After 1 day , observe the contents of each dish
  without removing the covers. Estimate the
  percentage of the agar surface that shows any
  changes. Record your observations.
• Wash your hands with soap and water.

9
The End