Tests and Stains

Question 1

Special staining methods for CAPSULE

Answer 1

1. Hiss stain
2. India ink stain

Question 2

Endospore stains

Answer 2

1. Schaeffer-Fulton stain
2. Wirtz-Conklin
3. Doemer’s stain

“DWS”

Question 3

Differentiate Nocardia and Actinomyces (fungi-like / branching bacteria)

Answer 3

Oxygen requirement and Acid-Fast

Nocadia = obligate aerobe, AF

Actinomyces - obligate anaerobe, non-AF

Question 4

Stain wherein th primary stain binds to mycolic acid in the cell wall of mycobacteria and is retained after decolorization

Answer 4

Acid-Fast Stain

Question 5

Gram Stain components

Answer 5

Primary: Crystal Violet
Mordant: Gram’s iodine
Decolorizer: Alcohol-acetone
Secondary: Safranin

Question 6

Acid-Fast components

Answer 6

Primary: Carbol Fuchsin

Mordant: Heat (Zhiel-Neelsen); Phenol (Kinyoun)

Decolorizer: Acid-alcohol

Secondary: Methylene blue / malachite green

Question 7

AFB smear size

Answer 7

Thumb size or 2cm x 3cm

Question 8

Binds to mycolic acid in organism’s cell wall, staining the bacteria YELLOW or ORANGE

Answer 8

Rhodamine-auramine (fluorescent stain)

Question 9

Bind to nucleic acid and fluorsces as BRIGHT ORANGE when using FLUORESCENT MICROSCOPE

Answer 9

Acridine Orange

Question 10

Used to locate bacteria in blood cultures and other specimens where discerning bacteria can be difficult

Answer 10

Acridine Orange (fluorescent dye)

Question 11

Allowing visualization of fungal structures (by binding to chitin in fungal cell wall) when using FLUORESCENT MICROSCOPE

Answer 11

Calcofluor White

Question 12

Fluoresces as BRIGHT APPLE-GREEN or BLUE-WHITE

Answer 12

Calcofluor White

Question 13

Traditionally used to stain C. diptheriae for
observation of metachromatic granules

Answer 13

Methylene Blue

Question 14

Negative stain used to visualize capsule surrounding certain yeast (ex. Cryptococcus)

Answer 14

India Ink

Question 15

Endospores Stain components
(Schaeffer-Fulton stain/ Wirtz-Conklin stain)

Answer 15

Primary stain: Malachite green
Secondary stain: Safranin

Question 16

Endospore stain color result

Answer 16

Endospores appear green with pink-appearing or red-appearing bacterial cells

Question 17

Immunofluorescent (IF) antibody staining is most useful in confirming the presence of

Answer 17

Bordetella pertussis and Legionella pneumophila

Question 18

Composition of O-F medium

Answer 18

• Low peptone
• 1% carbohydrate
• Bromthymol blue indicator

Question 19

TRIPLE POSITIVE:
- Catalase (+), Oxidase (+), Urease (+)

Answer 19

Helicobacter pylori