Assignment part I: Gram staining
Q1. Name the four reagents used in the Gram stain and describe their role.
Q2. Describe the most critical step in the Gram stain and describe the result if it is done incorrectly.
Q3. Describe how culture age plays a role in converting Gram positive organisms to Gram negative.
Q4. Describe the shape and color of the Gram-stained Staphylococcus epidermidis and Escherichia coli.
Q5. Name the bacterial cellular characteristic responsible for the Gram stain. Explain how this characteristic plays a role in staining Gram-positive cells and not Gram negative cells
Assignment part II: Negative Staining
Q1. Describe the microscopic appearance of a negative stain.
Q2. What cells are best observed using this staining technique?
Q3. Why are cells not heat fixed when performing a negative stain?
Assignment part III: Motility
Q1. Describe the medium used to detect motility. How do motile and nonmotile bacteria behave in this medium?
Q2. Briefly name and describe the two slide methods used to observe motility. Why might the hanging drop method be preferred?