Question 1

Which primary stain is used in the acid-fast staining procedure to color all cells fuchsia?

Accepted Answer

Carbolfuchsin

Question 2

What is the main chemical component in the cell wall of acid-fast bacteria that makes them resistant to decolorization by acid-alcohol?

Accepted Answer

Mycolic acid

Question 3

In the Kinyoun method of acid-fast staining, what is the purpose of the counterstain methylene blue?

Accepted Answer

To stain non-acid-fast bacteria blue

Question 4

Which of the following best describes the appearance of acid-fast bacteria after completing the acid-fast stain using the Kinyoun method?

Accepted Answer

Fuchsia rods

Question 5

Refer to the first image provided. What type of bacteria is indicated by the fuchsia-colored rods?

Accepted Answer

Acid-fast bacilli

Question 6

Refer to the second image provided. What does the blue staining indicate about the bacteria present?

Accepted Answer

They are non-acid-fast bacteria

Question 7

Which of the following steps is omitted in the Kinyoun method compared to the Ziehl-Neelsen method?

Accepted Answer

Use of heat during staining

Question 8

If you skip the counterstain step in the acid-fast staining procedure, what color will non-acid-fast bacteria appear?

Accepted Answer

Clear

Question 9

Which of the following diseases is caused by an acid-fast bacillus?

Accepted Answer

Tuberculosis

Question 10

Why is the acid-fast stain clinically significant?

Accepted Answer

It helps diagnose diseases caused by Mycobacterium species

Question 11

Which of the following is a correct sequence of steps in the Kinyoun acid-fast staining method?

Accepted Answer

Carbolfuchsin → Acid-alcohol → Methylene blue

Question 12

Which of the following equations best represents the relationship between the total magnification ($$M$$), the ocular lens magnification ($$M_o$$), and the objective lens magnification ($$M_{obj}) $$when observing acid-fast stained slides?

Accepted Answer

$$M = M_o 	imes M_{obj}$$

Question 13

A patient sample is stained using the acid-fast method and observed under oil immersion. You see fuchsia rods and blue cocci. What is the most likely interpretation?

Accepted Answer

The sample contains both acid-fast bacilli and non-acid-fast cocci

Question 14

Which of the following statements about acid-fast bacteria is FALSE?

Accepted Answer

They are always Gram-negative

Question 15

Which of the following is NOT a differential stain?

Accepted Answer

Simple stain

Question 16

Which of the following best explains why Mycobacterium tuberculosis is acid-fast?

Accepted Answer

It contains mycolic acids in its cell wall

Question 17

Which of the following is a correct pairing of disease and causative agent identified by acid-fast staining?

Accepted Answer

Tuberculosis – Mycobacterium tuberculosis

Question 18

Which of the following parasites can be identified using the acid-fast stain, and what disease do they cause?

Accepted Answer

Cryptosporidium – Cryptosporidiosis

Question 19

A laboratory technician accidentally uses water instead of acid-alcohol during the decolorization step of the acid-fast stain. What is the most likely result?

Accepted Answer

Both acid-fast and non-acid-fast bacteria will appear fuchsia

Question 20

Which of the following best describes the clinical importance of differentiating acid-fast from non-acid-fast bacteria?

Accepted Answer

It allows for the identification of pathogens like Mycobacterium tuberculosis

Acid-Fast Stain: Principles, Procedure, and Clinical Significance

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