Page 77 - MNUmicrobiology practical 2025

General Microbiology & Immunology (PM 401) second level Semester 4 2024/2025

Choose the best correct answer in the following statements:

1- In differential staining procedure more than one dye is used for staining. Which

of the following is Differential staining procedure?
a) Gram staining

b) Acid fast staining
c) Both Gram staining and acid fast staining
d) All answers are false

2- Certain Gram positive bacteria does NOT take up stain during Gram staining
method due to:
a) Thick peptidoglycan layer in cell wall

b) Thin peptidoglycan layer in cell wall
c) Waxy cell wall made of mycolic acid
d) Lack of cell wall

3- After successful acid fast staining, non acid fast bacteria appear.….in color.
a) Red
b) Blue

c) Green
d) Yellow

The following microscopic image represent
acid fast staining of microbial culture, it
reveals two organisms A and B

1- Which of the these organism is acid fast and non acid fast?

2- Draw a diagram representing the cell wall of A and B

General Microbiology & Immunology (PM 401) Practical note Page 66