Name ______Date ______Period ______
Bacteria Lab
Problem: Comparing a variety of surfaces found in a school building, what surface would have the most bacteria on it?
Hypothesis: If bacterial growth is higher in an area that receives more daily contact and bacterial growth is tested by swabbing and incubation, then I hypothesize that the most bacteria will be found on ______and the least on ______.
Experiment:
Materials – beaker with water, 4 swabs, Petri dish with nutrient agar, marker
Procedure –
1. Use a marker to divide bottom of Petri dish into quadrants.
2. Number the quadrants 1, 2, 3, and 4
3. Put your last names, Coach Gray, and Period on the side of the Petri dish
4. Quadrant 1 is your control. Dip one swab into the beaker of water and quickly open the Petri dish and streak only quadrant 1. Quickly re-close Petri dish and dispose of used swab.
5. Select the other 3 areas you want to swab: 2. ______, 3.______, 4.______
6. Obtain a pass from the teacher
7. When you arrive at the location for sample 2, pull out sterile swab and dip into water. Thoroughly cover area with moistened swab and then quickly open Petri dish and streak quadrant 2. Quickly reclose Petri dish and dispose of used swab
8. repeat step 7 for the other 2 areas.
9. Upon return to class, place parafilm on the sides of petri dish, invert Petri dish and place in incubator. Return marker and beaker to teacher
Name ______Date ______Period ______
Bacteria Lab
Problem: Comparing a variety of surfaces found in a school building, what surface would have the most bacteria on it?
Hypothesis: If bacterial growth is higher in an area that receives more daily contact and bacterial growth is tested by swabbing and incubation, then I hypothesize that the most bacteria will be found on ______and the least on ______.
Experiment:
Materials – beaker with water, 4 swabs, Petri dish with nutrient agar, marker
Procedure –
1. Use a marker to divide bottom of Petri dish into quadrants.
2. Number the quadrants 1, 2, 3, and 4
3. Put your last names, Coach Gray, and Period on the side of the Petri dish
4. Quadrant 1 is your control. Dip one swab into the beaker of water and quickly open the Petri dish and streak only quadrant 1. Quickly re-close Petri dish and dispose of used swab.
5. Select the other 3 areas you want to swab: 2. ______, 3.______, 4.______
6. Obtain a pass from the teacher
7. When you arrive at the location for sample 2, pull out sterile swab and dip into water. Thoroughly cover area with moistened swab and then quickly open Petri dish and streak quadrant 2. Quickly reclose Petri dish and dispose of used swab
8. repeat step 7 for the other 2 areas.
9. Upon return to class, place parafilm on the sides of petri dish, invert Petri dish and place in incubator. Return marker and beaker to teacher
Conclusion:
1. What kingdom of bacteria were we testing for? ______
2. Which quadrant had the most bacteria? Which had the least? Were your results surprising?
3. Provide some possible explanation for your results.
4. What were some of the things that went wrong with this lab (called experimental error)
5. Why did you need the control?
6. Why was it important to quickly re-close the Petri dish after streaking the plate?
7. What would have happened if you hadn’t had nutrient agar in the bottom of the Petri dish?
8. What would have happened if you hadn’t used an incubator?
9. Draw below your petri dish, be sure to label each quadrant and list how many colonies were in each:
Conclusion:
1. What kingdom of bacteria were we testing for? ______
2. Which quadrant had the most bacteria? Which had the least? Were your results surprising?
3. Provide some possible explanation for your results.
4. What were some of the things that went wrong with this lab (called experimental error)
5. Why did you need the control?
6. Why was it important to quickly re-close the Petri dish after streaking the plate?
7. What would have happened if you hadn’t had nutrient agar in the bottom of the Petri dish?
8. What would have happened if you hadn’t used an incubator?
9. Draw below your petri dish, be sure to label each quadran and list how many colonies were in each: