Reference no: EM133443111

Morphological studies of bacteria- Preparation of smear, simple and differential (Gram) staining.

1. Name two preparations that may be used to observe microorganisms under the microscope.

2. What is the purpose of heat fixing? Why must slides used in smear preparation be grease-free?

3. Is it necessary to use sterile water when making a smear? Why or why not?

4. What is the purpose of staining bacteria following the simple stain technique?

5. What are the differences between a simple stain and a differential stain? Give an example of a differential staining technique.

6. On which difference in bacterial composition does the Gram staining technique rely?

7. List in order the reagents used in the Gram stain and tell the function of each.

8. What would be the proper way to report each of the following if they had been Gram stained?

Purple (blue), round cells

Pink (red), rod-shaped cell

Pink (red), round cells

Purple (blue), rod-shaped cells

9. What color will you observe under the light microscope after the:

Gram staining of Gram -ve bacterial cell:

Gram staining Gram +ve bacterial cell:

Crystal violet staining of Gram -ve bacterial cell:

Crystal violet staining Gram +ve bacterial cell: