Common Stains Used For Microscopic Visualization

Question 1

Most commonly used stain in clin. Microbiology lab.

Answer 1

Gram stain

Question 2

What are the sequential components of gram stain?

Answer 2

V- crystal violet (primary)
I- Gram Iodine (mordant/fixative)
A- Acetone alcohol (decolorizer)
S- Safranin (counterstain)

Question 3

T or F
In gram stain, crystal violet is the primary stain. It should be done in 1 min.

Answer 3

Both statements are True

Question 4

In Gram stain, what is the mordant/fixative? How long does it take?

Answer 4

Gram iodine-1 minute

Question 5

T or F
Alcohol acetone is the decolorizer in gram stain, and it should be done quickly and need to rinse.

Answer 5

True

Question 6

Couterstain in gram stain.

Answer 6

Safranin (30s)

Question 7

T or F
In gram stain (rinsing with water between in each step is not necessarily.

Answer 7

False- it is required

Question 8

(Gram stain)
Bacteria is initially stain ___ by the crystal violet, which is bound to the cell wall with the aid of ____

Answer 8

Purple, iodine

Question 9

(Gram stain)
When decolorizer applied to gram ____ type of cell wall structure, the ______ ______ wash out of the cell.

Answer 9

Negative, crystal violet

Question 10

Why is Gram negative color pink in gram staining?

Answer 10

Because the decolorizer washed out the primary stain, which Safranin serves as counter stains, who takes up the color pink by gram-negative bacteria.

Question 11

T or F
(Gram stain)
Gram positive will retain the primary crystal violet stain during decolorizing treatment and appear purple.

Answer 11

True

Question 12

T or F
(Gram stain)
Cells in direct smear from a patient specimen, like epithelial cells, WBC, RBC should appear purple (positive) if gram stain was performed correctly.

Answer 12

False pink (negative)

Question 13

4 major steps in staining.

Answer 13

Primary stain
Mordant stain
Decolorization
Counter/secondary stain

Question 14

Stain that enhances the primary stain to absorb properly.

Answer 14

Mordant stain

Question 15

Remove the primary stain and most crucial.

Answer 15

Decolorization

Question 16

Fix the smear and slides

Answer 16

Fixation

Question 17

General rule:
All cocci are gram positive except

Answer 17

Neisseria, Moraxella, Veillonella
(They are gram negative)

(MNeV)

Question 18

General rule:
All bacilli are negative except

Answer 18

“BLLaCCMENPro” (positve bacilli)
- Bacillus
- Listeria
- Lactobacillus
- Clostridium
- Corynebacterium
- Mycobacterium
- Erysipelothrix
- Nocardia
- Propionibacterium

Question 19

Stains that are used to stain bacteria that have high lipid and wax content in their cell walls and do not stain in traditional stain.

Answer 19

Acid-fast stain

Question 20

Four sequential stains in Acid fast stain.

Answer 20

-Carbolfuchsin (red/pink dye) (primary stain)
-Hot method and detergent (mordan stain)
- Acid Alcohol decolorizer
-methylene blue (counter stain)/ malchite green alternative

Question 21

2 mordant stain of acid fast.

Answer 21

Hot method (steam)
Cold method (detergent)

Question 22

Other terms of 2 mordant stains in acid fast.

Answer 22

Hot method (Ziehl-Neelsen method)
Cold method (Kinyoun method)

Question 23

What happened to non acid fast bacteria if stain in acid fast stain?

Answer 23

It will decolorize and turn to blue because of the counter stain.

Question 24

Which statement is/are true?
A. Mycolic acid attracts the stain pink/red of safranin.
B. Often alchol used in acid-fast is HCL.
C. Sulfuric acid is an alternative acid because some bacteria are sensitive to strong acid.
D. Sputum is usually used specimen in acid fast.

Answer 24

All answers are correct

Question 25

What are the 3 acid fast bacilli?

Answer 25

Mycobacterium Nocardia Rhodococcus

Question 26

Acid fast staining is used to identify_____. A. Cystoisospera belli B. Saccharomyces C. Coccidan parasites D. Cryptosporidium

Answer 26

All of the above

Question 27

Other staining metthod used for screening acid fast bacteria.

Answer 27

Fluorochrome

Question 28

Other terms of fluorochrome

Answer 28

Auramine-rhodamine

Question 29

T or F Acid fast bacteria appear red under fluorescent microscope

Answer 29

False -bright yellow or orange

Question 30

Acredine orange stain is used for what?

Answer 30

Blood culture

Question 31

What positive color in Acredine orange?

Answer 31

Yellow orange

Question 32

T or F Acridine orange stain only in gram positve and only in living bacteria.

Answer 32

False- it can be stained either positive or negative and living or dead

Question 33

This staining technique binds chitin in the fungal cell wall.

Answer 33

Calcofluor white

Question 34

What color of calcofluor white allows to visualize fungal structure in microscope.

Answer 34

Bright apple green /blue white

Question 35

It was original "blueing" used in high volume laundries.

Answer 35

Calcofluor white

Question 36

Detects the presence of fungi hyphae.

Answer 36

Calcofluor white

Question 37

Used to detect metachromic granules of Corynebacterium dipththeriae.

Answer 37

Methylene blue

Question 38

Used to stain the cell walls of medically important fungi grown in slide culture.

Answer 38

Lactophenol cotton blue

Question 39

It is used in negative staining

Answer 39

Indian ink

Question 40

Used to visualize the capsule surrounding certain yeasts like Cryptococcus spp.

Answer 40

India ink

Question 41

Common endospore stain

Answer 41

Shaeffer fulton

Question 42

T or F The primary stain in endospore stain is methyl blue.

Answer 42

False- it is malachite green

Question 43

T or F (Endospore stain) To heat fix the smear, it takes 5 mins.

Answer 43

True

Question 44

T or F (Endospore stain) The slide must wash about 1min.

Answer 44

False- 30sec.

Question 45

What is the counter stain in the endospore stain.

Answer 45

Safranin

Question 46

What is the color of spores in endospore stain? A. It appears green within pink/red appearing bacterial cells. B. It appears dark pink in the cell wall of bacteria C. It appears pink within blue appearing bacteria cell walll D. It appears green within the blue appearing bacterial cells.

Answer 46

A.