Acid-Fast staining (Kingoun method) quiz

Question 1

what is the reason for the necessity of acid-fast staining technique?

Answer 1

mycolic acid within acid-fast bacteria prevents penetration of stains, so we need a way to make these bacteria more permeable

Question 2

why are acid-fast bacteria called acid-fast?

Answer 2

because they are resistant to acid wash

Question 3

what two specimens will we be using to perform the Kingoun method? which is the acid-fast bacteria?

Answer 3

Mycobacterium smegmatis - acid-fast
Staphylococcus epidermidis

Question 4

What is used as the primary stain? what color does it stain and which of the bacteria does it stain?

Answer 4

basic fuchsin
stains Mycobacterium (red)

Question 5

how long is the primary stain applied?

Answer 5

5 minutes

Question 6

what decolorizer is used in the acid-fast method?

Answer 6

acid-alcohol is used to decolorize the cells and background that is not Mycobacterium

Question 7

How long do we spray the decolorizer?

Answer 7

spray acid-alcohol for 1 minute (or until no more stain runs off slide)

Question 8

How do we neutralize the decolorizer afterwards?

Answer 8

rinsing briefly with distilled water

Question 9

what is the counterstain used? what color does it make to which bacteria?

Answer 9

methylene blue
makes the Staphylococcus (blue)

Question 10

how long do we counterstain?

Answer 10

30 seconds

Question 11

what do we do once we finish counterstaining?

Answer 11

rinse briefly with distilled water
blot dry with bibulous paper

Question 12

why doesn’t the Kinguon method require heat?

Answer 12

basic fuchsin and phenol is increased instead