Staining technique (LAB) Flashcards

1
Q

Decolorizing agent of AFB stain

A

Acid-Alcohol (3% hCl + 95% Ethanol)

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2
Q

used to intensify the color of the primary stain of Gram’s

A

mordant

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3
Q

What result will be if at least one sputum smear is positive for AFB

A

Positive

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4
Q

Fixation is done through______ or _____

A

Slide warmer /Heating , or
95% methanol

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5
Q

_______contribute to the ability of gram positive organisms to resist alcohol decolorization

A

teichoic acid cross-links / teichoic acid cross-links

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6
Q

Gram stain is considered a __________

A

differential stain

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7
Q

render the
cells resistant to
decolorization in AFB stain

A

Mycolic acid

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8
Q

Nearly all clinically important bacteria can be detected using gram staining method, the only exceptions being those organisms that exist ________, _____, and ________

A

Exclusively within host cell, lack cell wall , and Insufficient dimension on light microscope

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9
Q

Negative result for AFB requires _____ negative

A

both sputum smears (2 samples)

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10
Q

Kind of fixation that preserves the morphology
of host cells, as well as bacteria, and is especially useful for
examining bloody specimens

A

Methanol fixation

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11
Q

He first devised gram staining during the late nineteenth century

A

Hans Christian Gram

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12
Q

In order to establish a color contrast, the
third reagent used in Gram staining is the

A

decolorizing agent

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13
Q

enhance sputum quality detection by acid-fast stain and culture

A

Decontamination / Digestion

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14
Q

preparation of the primary clinical sample received in the laboratory for processing

A

Direct Smear

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15
Q

contains a highly crossed linked layer of peptidoglycan that retains the primary dye

A

Gram positive

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16
Q

Commonly, indirect smears use ___

A

pipette

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17
Q

Application of
safranin: Gram-positive cells are ____ ; gram-negative cells are _____

A

purple, pink

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18
Q

Commonly, direct smears use ____

A

swabs

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19
Q

during 95% alcohol wash: Gram-positive cells are purple; gram-negative
cells are _____

20
Q

the acid-fast stain is only performed on specimens from
patients highly suspected of having a _____

A

mycobacterial infection

21
Q

a staining step of Gram’s that distinguishes gram-positive
from gram-negative cells

A

decolorization

22
Q

chemical differentiation of organisms

A

Differential Stain

23
Q

AFB staining’s primary stain

A

Carbol Fuchsin

24
Q

Bacterial group that take up the basic dye, crystal violet

A

gram positive bacteria

25
designed for a subset ofbacteria whose cell walls contain long chain fatty (mycolic) acids
Acid-Fast Staining
26
Indirect smears may include preparation from _______
solid or semisolid media or broth
27
For staining microorganisms grown in culture or an indirect smear, a sterile ________ may be used to transfer a small amount of growth from a solid medium to the surface of the slide
loop or needle
28
AFB interpretation: 10-99 AFB in 1 length
1+
29
The procedure requires heat to allow the primary stain (carbolfuchsin) to enter the wax-containing cell wall
ZIEHL-NEELSEN
30
Standard measurement for AFB smearing
3cm x 2cm
31
Mordant for Gram stain
Gram iodine
32
Decolorizer for Gram stain
acetone/alcohol
33
Acid-fast–positive bacilli color
Red
34
The Gram stain differentiates between bacteria based on the composition of their
cell walls
35
Gram negative color
Pink
36
applied after the crystal violet to chemically bond the alkaline dye to the iodine, forming a CV-I complex and cross-linking the complex in the bacterial cell wall
mordant (Gram's iodine (I) )
37
Acid-Fast negative bacilli color
Blue
38
Primary stain for Gram's
Crystal violet
39
counterstain for Gram's
safranin
40
AFB stain counterstain
Methylene Blue
41
Cold method of AFB stain that does not require the use of heat or boiling water, minimizing safety concerns during the procedure
Kinyoun acid-fast method
42
All smears should be ________ before staining
air dried
43
indicates that the primary sample has been processed in culture and the smear contains organisms obtained after purification or growth on artificial media
indirect smear
44
AFB interpretation: 1-10 AFB/OIF at least 50 fields
2+
45
A direct smear provides a mechanism to identify the number and type of cells present in a specimen including ____-, _____, and ______
white blood cells epithelial cells predominant organism
46
principal stain used for microscopic examination of bacteria and is one of the most important bacteriologic techniques within the microbiology laboratory
Gram stain
47
The order of Dyes, Mordant & Decolorizer in Gram-staining procedure is
Crystal violet, Iodine solution, Alcohol, Safranine