1.What should be done if Gram-positive organisms are staining as
Gram-negative?
A) Increase the decolorization time
B)
Lengthen the crystal violet and mordant step and shorten the
decolorizer step
C) Use a different stain
D) Use older cultures
B) Lengthen the crystal violet and mordant step and shorten the decolorizer step
1.What is a possible cause if no organism is visible?
A)
Overheating the smear
B) Failure to heat fix
C) Using too
many organisms
D) Using old culture
B) Failure to heat fix
1.What could cause organisms to appear clumped on a slide?
A)
Too many organisms on slide
B) Failure to heat fix
C) Over
decolorized
D) Improper decolorization
A) Too many organisms on slide
1.If the smear appears granular under oil, what might be the cause?
A) Overheating the smear
B) Using old culture
C)
Lens is dirty or condenser lens too low
D) Excessive rubbing of smear
C) Lens is dirty or condenser lens too low
1.What should be done if Gram-positive organisms appear pink?
A) Use fresh culture
B) Increase time with crystal violet
C) Decolorize longer
D) Apply heat when doing primary stain
B) Increase time with crystal violet
1.What could cause Gram-negative organisms to appear blue?
A)
Over decolorized
B) Improper decolorization
C) Using old
culture
D) Failure to heat fix
B) Improper decolorization
1.What should be done if no spores are visible after a spore stain?
A) Use older culture
B) Use fresh reagents
C)
Increase time with crystal violet
D) Decolorize longer
B) Use fresh reagents
1.What might cause Gram-positive organisms to appear too faint?
A) Crystal violet stain time is too short
B) Over
decolorized
C) Improper decolorization
D) Failure to heat fix
A) Crystal violet stain time is too short
1.Why is the acid-fast stain named as such?
A) Because it uses
acidic dyes
B) Because it resists decolorization by acids
C) Because it stains acidic bacteria
D) Because it uses
acid to fix the smear
B) Because it resists decolorization by acids
1.What component in Mycobacteria cell walls contributes to their
acid-fastness?
A) Proteins
B) Carbohydrates
C)
Lipids and mycolic acids
D) Nucleic acids
C) Lipids and mycolic acids
1.In the Ziehl–Neelsen method, what is the purpose of placing the
slide on a staining rack containing boiling water?
A) To fix the
smear
B) To heat the carbolfuchsin
C) To decolorize the
smear
D) To dry the smear
B) To heat the carbolfuchsin
1.How long should the smear be covered with carbolfuchsin in the
Ziehl–Neelsen method?
A) 1-2 minutes
B) 3-4 minutes
C) 5-7 minutes
D) 8-10 minutes
C) 5-7 minutes
1.What is used to decolorize the smear in both the Ziehl–Neelsen and
Kinyon methods?
A) Ethanol
B) Acid alcohol
C)
Acetone
D) Water
B) Acid alcohol
1.What is the counterstain used in both the Ziehl–Neelsen and Kinyon
methods?
A) Crystal violet
B) Safranin
C) Methylene
blue
D) Malachite green
C) Methylene blue
1.In the Kinyon method, how long should the smear be decolorized
initially?
A) 1 minute
B) 2 minutes
C) 3 minutes
D) 4 minutes
B) 2 minutes
1.What is the appearance of acid-fast bacilli after staining?
A) Blue with a red background
B) Red with a blue
background
C) Green with a blue background
D) Purple with
a pink background
B) Red with a blue background
1.What would be the Gram stain reaction of Mycobacterium?
A)
Gram-positive
B) Gram-negative
C) Acid-fast
D) Non-reactive
C) Acid-fast
1.How would organisms other than Mycobacterium appear when subjected
to acid-fast staining?
A) Red
B) Blue
C) Green
D) Purple
B) Blue