BACTE LAB - AFS

Question 1

Slides must be

Answer 1

new
clean
free from grease
free from fingerprints
unscratched

Question 2

what to write on the frosted end of the slide

Answer 2

laboratory register serial number

order number of the sputum specimen

Question 3

type of pencil to use on unfrosted slides

Answer 3

diamond pencil, left end of the slide

Question 4

what part of the sputum must be taken

Answer 4

yellowish purulent part

Question 5

smear shape

Answer 5

oval

Question 6

smear size

Answer 6

2 cm wide x 3 cm length

Question 7

the smear size corresponds to how many visual fields

Answer 7

150, to be counted in one length

Question 8

if wire loop was used instead of applicator stick, dip it in ___

Answer 8

alcohol washed-sand bottle

Question 9

clean the wire loop in a flask containing ___ before sterilizing in a flame

Answer 9

70% - 90% alcohol with glass beads or sand

Question 10

for accidental contamination with sputum,

hand:

Answer 10

wash with soap and water

Question 11

for accidental contamination with sputum,

cloth:

Answer 11

spray with 5% phenol OR
Soak in disinfectant OR
Autoclave OR
Boil

Question 12

for accidental contamination with sputum,

Surface of container,

Answer 12

wear rubber gloves before handling it

Question 13

for accidental contamination with sputum,

bench of floor

Answer 13

spray with 5% phenol or Lysol

Question 14

How to dry the smears

Answer 14

air dry, not in direct sunlight or over a flame

Question 15

Elements of Quality Smear

Answer 15

Quality of sputum
size of smear
thickness of smear
evenness of smear
staining technique
cleanness of slide

Question 16

What will happen if during fixation the slide was heated for too long or kept stationary

Answer 16

smear will be scorched

Question 17

a good stained smear by ZN method shows ___

Answer 17

strong red AFB, against weak blue background

Question 18

It is not possible to decolorize if _____ are used

Answer 18

cold watery acids

Question 19

To prepare 0.3% Ziehl’s carbol fuchsin working solution, mix

Answer 19

10 ml solution A and 90 ml solution B

Question 20

Solution A of Ziehl’s carbol fuchsin

Answer 20

Fuchsin Alcoholic Stock Solution

Question 21

Solution A of Ziehl’s carbol fuchsin components

Answer 21

3g basic fuchsin

95% alcohol UP to 100 mL

Question 22

Solution A of Ziehl’s carbol fuchsin NAME

Answer 22

Aqueous Phenol Solution

Question 23

Solution A of Ziehl’s carbol fuchsin components

Answer 23

Phenol crystals 5g

Distilled water up to 90 mL

Question 24

Before adding water, liquefy the phenol crystals by

Answer 24

gentle heating

Question 25

Decolorizing Agent Solutions

Answer 25

Acid-alcohol solution | 25% Aqueous Sulfuric Acid Solution

Question 26

Acid-alcohol solution components

Answer 26

95% alcohol --- 970 mL | 35% HCl --- 30 mL

Question 27

25% Aqueous Sulfuric Acid Solution components

Answer 27

distilled water 300 ml | conc. sulfuric acid 100 ml

Question 28

0.3% Methylene Blue Counterstaining Solution components

Answer 28

0.3 g methylene blue chloride | distilled water up to 100 mL

Question 29

ZN method requires staining for ___ min

Answer 29

10

Question 30

ZN method requires decolorizing for ___ min

Answer 30

approx 3 min

Question 31

ZN method requires counterstaining for ___ min

Answer 31

not more than 1 min

Question 32

what replaced carbon fuchsin in fluorescence staining

Answer 32

fluorescent dye

Question 33

examples of fluorescent dye

Answer 33

auramine-O rhodamine auramine-rhodamine acridine orange

Question 34

counterstain in fluorescence staining

Answer 34

potassium permanganate

Question 35

describe the decolorize in fluorescence staining

Answer 35

milder

Question 36

with auramine staining, the bacilli appears as (color)

Answer 36

slender bright yellow luminous rods against a dark background

Question 37

identification of mycobacteria with auramine O is due to the

Answer 37

affinity of mycolic acid in the cell walls for fluorochromes

Question 38

light produced by a substance when it is stimulated by another light

Answer 38

fluorescence

Question 39

fluorescence called cold light because

Answer 39

does not come from a hot source like an incandescent light bulb

Question 40

dyes which have the property of absorbing light rays of shorter wavelength and emitting light rays of longer wavelength

Answer 40

fluorescent dye such as auramine O

Question 41

source of light

Answer 41

mercury vapour lamp

Question 42

by meas of ____

Answer 42

only light rays of shorter wave lengths are allowed to emerge

Question 43

rays of ___ wavelengths used for fluorescence microscopy

Answer 43

shorter

Question 44

Heat slides until

Answer 44

Vapor starts to rise and metallic sheen appears

Question 44

Heat slides until

Answer 44

Vapor starts to rise and metallic sheen appeara

Question 45

Let the carbol fuchsin staim stand for ---min

Answer 45

10 min

Question 46

Applying time for counterstaining reagent depends on (3)

Answer 46

Quality of specimen Thickness of smear Concentration of reagent

Question 47

Poor quality smears can lead to ----

Answer 47

False results

Question 48

If the smear is dark blue, this means that,

Answer 48

The smear is too thick

Question 49

Employed to highlight the stained organisms for easier recognition

Answer 49

Counterstain

Question 50

Examples of fluorescent dye

Answer 50

Auramine-O Rhodamine Auramine-rhodamine Acridine orange

Question 51

Counterstain in fluorescence microscopy

Answer 51

Potassium permanganate

Question 52

Useful to quench background fluorescene

Answer 52

Counterstain (potassium permanganate)

Question 53

Fluorescent dyes are also called

Answer 53

Fluorochromes

Question 54

Principle lf auramine staining

Answer 54

Affinity of mycolic acids for fluorochromes

Question 55

After smearing sputum, let the slide air dry for ---- min

Answer 55

15-20 min

Question 56

T or F | Wet slides can produce aerosols if disturbed

Answer 56

T

Question 57

When is Bsc required

Answer 57

Large volume of positive sputum sx to be handled In cultures In drug susceptibility testing

Question 58

Specimens can be discarded by (2)

Answer 58

Burying after chemical disinfection or autoclaving | Safe commercial waste collection services

Question 59

Discard waste in a deep pit of at least --- m depth

Answer 59

1.5

Question 60

Limit the number of slides in each staining batch to a maximum of ---

Answer 60

12