Solution-Positive or negative controls | Homework Helpers

1. Are the controls in this experiment, positive or negative controls? How do you know? (what is the purpose of each)?

2. Which bacterial plates contained oxidase positive bacteria? Which plates contained oxidase negative bacteria? Were the colonies from the plates similar? How do you interpret the colony growth?

3. Which of your samples had cytochrome c oxidase? Which samples did not?

4. What reaction would you expect when performing a negative control in the catalase assay?

5. What reaction would you expect when performing a positive control in the catalase experiment? What would it mean if a known catalase positive did not produce bubbles after the aIDition of H2O2?