BACTERIAL STAINING

Question 1

What is the purpose of staining?

Answer 1

1. To determine bacterial morphology
2. To differentiate groups of bacteria
3. To identify organisms with special structures

Question 2

What are the 2 kinds of ionizable dyes?

Answer 2

Basic dye and acidic dye

Question 3

It is commonly used in bacteriology

Answer 3

Basic dyes

Question 4

It adhere to negatively charged molecules like nucleic acids and protein

Answer 4

Basic dyes

Question 5

Examples of this are: Methylene blue, basic fuchsin, crystal violet, safranin and malachite green

Answer 5

Basic dyes

Question 6

It adheres to positively charged cell structures

Answer 6

Acidic dyes

Question 7

Examples of this are eosin, acid fuchsin, nigrosin dye

Answer 7

Acidic dyes

Question 8

What are the examples of basic dyes?

Answer 8

Safranin and malachite green
Methylene blue
Crystal violet
Basic fuchsin

Question 9

What are the examples of acidic dyes?

Answer 9

Eosin
Acid fuchsin
Nigrosin dye

Question 10

used for staining forms and shapes of cells, SINGLE stain only.

Answer 10

SIMPLE staining - meth blue

Question 11

DIVIDES bacteria into separate groups, to stain components of cells

Answer 11

DIFFERENTIAL staining - gram and AFB stain

Question 12

DEMONstrate the presence of diffuse capsule, bacterial gas vacuoles, and viral morphology

Answer 12

NEGATIVE staining - India ink and Nigrosin dye

Question 13

India ink and nigrosin dye are examples of what type of staining?

Answer 13

Negative staining

Question 14

Gram stain and AFB stain are examples of what type of staining?

Answer 14

Differential staining

Question 15

Methylene blue is an example of what type of stain?

Answer 15

Simple staining

Question 16

Who developed the gram staining method, and what year?

Answer 16

Danish Christian GRAM in 1884

Question 17

What is the other name of crystal violet?

Answer 17

hexamethyl-p-rosanaline chloride

Question 18

a sequential step is to provide color to all cells and background material a deep blue

Answer 18

Crystal violet

Question 19

it is to provide the larger iodine element, to replace the smaller chloride in the stain molecule

Answer 19

Gram’s iodine

Question 20

What bacteria contents retain crystal violet-iodine complex dye after decolorization and appear deep blue?

Answer 20

Bacteria with THICK cell walls = Gram positive bacteria

Question 21

a bacteria with thinner walls containing lipopolysaccharides and does not retain the dye complex are?

Answer 21

Gram-negative bacteria

Question 22

It damages these thin lipid walls and allows the stain complex to wash out

Answer 22

alcohol-acetone decolorizer

Question 23

T or F: Principle of gram stain–all unstained elements are subsequently counterstained red by safranin dye

Answer 23

True

Question 24

The differential ability of Gram stain is useful in?

Answer 24

Microbial taxonomy

Question 25

the quickness and ease of this method is the ideal choice for the clinical lab settings

Answer 25

Gram staining

Question 26

T or F: CSF, sterile fluid, expectorated sputum or bonchoalveolar lavages, and wounds and exudates are routinely stained DIRECTLY

Answer 26

true

Question 27

T or F: Urine ans stool can be routinely stained directly

Answer 27

False - may not be for direct staining

Question 28

Where is gram stain regularly used?

Answer 28

in characterizing bacteria on culture media

Question 29

How to improve adherence in gram staining?

Answer 29

1. Fixation using 70 to 95% alcohol 2. Heat fixation

Question 30

Suspicious areas are evaluated using the?

Answer 30

x100 oil objective lens of the microscope

Question 31

what gram-negative bacteria have strong avidity and stains bright red?

Answer 31

enterics

Question 32

what are less avid and stain moderately well

Answer 32

pseudomonads

Question 33

What are the anaerobic organisms that stain weakly?

Answer 33

Borrelia, Legionella, and Spirilum spp

Question 34

T or F: If the primary stain is rinsed vigorously prior to mordant application it will not be retained

Answer 34

True

Question 35

T or F: If decolorization is prolonged, gram negative complex will be removed

Answer 35

False - gram positive

Question 36

T or F: If the secondary dye is applied more than a minute, it will result to elimination of gram negative complex

Answer 36

False - gram positive

Question 37

State the reasons for false negative result

Answer 37

1. Aged, dying, autolyzing cells 2. By using acidic iodine during staining 3. Due to technical error or wrong use of stain

Question 38

What is the primary stain for gram staining and its application time?

Answer 38

Crystal violet - 1 min

Question 39

What is the mordant for gram staining, and its application time?

Answer 39

Iodine - 1 minute

Question 40

What is the decolorizer for gram staining and its wash time?

Answer 40

Acetone alcohol - until clear

Question 41

What is the secondary stain for gram staining and its application time?

Answer 41

Safranin - 1 minute

Question 42

What is used for staining organism with high lipid content on their cell wall?

Answer 42

AFB stain

Question 43

what is the hot staining method and cold staining method?

Answer 43

Ziehl-Neelsen Method - hot Kinyoun Method - cold

Question 44

What method differentiate M. smegmatis and M. tuberculosis?

Answer 44

Pappenheim Method

Question 45

What method diff M.leprae and M.tuberculosis?

Answer 45

Baumgarten Method

Question 46

it is a method Selective for the cell wall of AFB

Answer 46

Auramine-rhodamine Method

Question 47

Primary stain in AFB?

Answer 47

Carbol fuchsin

Question 48

Mordant stain in AFB?

Answer 48

Heat/tergitol for 10 minutes

Question 49

What is the decolorizer for AFB stain and its application time?

Answer 49

3% acid alcohol for 2 to 3 minutes

Question 50

What is the secondary stain for AFB stain?

Answer 50

Methylene blue for 1 minute