Module 11: Microorganism Staining

Question 1

What term describes the step where acetone is applied to the section until no more visible blue colour comes off?

Answer 1

Decolourizing

Question 2

What are the components of gram’s iodine?

Answer 2

Iodine, potassium iodide, distilled water

Question 3

What are acid fast bacilli stained with in the Ziehl-Neelsen method?

Answer 3

Carbol fuchsin

Question 4

What is the appearance of Mycobacterium tuberculosis stained by H+E?

Answer 4

Colourless

Question 5

What type of capsule do Mycobacterium tuberculosis and Mycobacterium leprae have?

Answer 5

Lipoid capsule

Question 6

List 3 measures that may be taken to ensure that contamination does not occur

Answer 6

Ensure slides are clean, run a negative control of a different block on the same microtome and placed on the same water bath, use Millipore filtered water

Question 7

Expected results of the Ziehl-Neelsen method

Answer 7

Acid-fast bacilli - red
Nuclei - blue
Caseous material - pale blue-grey
Other tissue components - pale blue

Question 8

Giemsa stain is used to demonstrate what?

Answer 8

Helicobacter pylori

Question 9

List 5 other ways Helicobacter pylori may be demonstrated

Answer 9

H+E, toluidine blue, cresol violet acetate, silver nitrate method (such as Warthog Starry), gram adaptation

Question 10

Expected results of the Giemsa stain

Answer 10

Helicobacter pylori, protozoa, other microorganisms - dark blue
Background - pink to pale blue
Nuclei - blue