Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology Lab > Special stains > Flashcards

Special stains Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

what species produce endospores?

A

Bacillus and Clostridium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why are endospores produced?

A

-they are produce when environments become unfavorable
-depletion of nutrients, change in temperature, lack of water
-when the environment becomes favorable again they will germinate back into vegetative cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Endospores

A

-are dormant forms of the bacteria resistant to heat, ultraviolet radiation, toxins, chemical disinfectants, freezing, and desiccation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In normal environmental conditions how do bacteria exists?

A

-in a vegetative state where they are able to reproduce and grow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What stain is used to identify endospores?

A

Schaeffer- Fulton stain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the Schaeffer- Fulton stain identify?

A

vegetative and endospore forms of Bacillus and Clostridium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Steps in Endospore stain (Schaeffer-Fulton)

A
  1. Place malachite green stain on the slide while holding over steam for 5 minutes (heat is the mordant)
  2. decolorize the stain with water (vegetative cells: white, endospores: green)
    3.Flood the smear with the counterstain safranin for 1 minute, then rinse with water
    (vegetative cell: red, endospore: green)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the mordant in the Schaffer Fulton stain

A

heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the primary stain in Schaffer- Fulton stain

A

malachite green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the counterstain in Schaeffer-Fulton stain

A

safranin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What species contain mycolic acid

A

mycobacterium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does mycolic acid do?

A

-is a waxy outer layer on cells that block primary stains from being absorbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can certain species of Mycobacterium cause?

A

-Leprosy or tuberculosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does acid-fast staining (Ziehl-Neelsen) identify?

A

-bacteria with mycolic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Steps in Acid-fast staining (Ziehl-Neelson)

A

1.Prepare a mixture of S.epidermis and Mycobacterium thin smear
2.Place carbolfuchsin stain on the slide while holding over steam for 5 minutes (heat is the mordant, which softens the waxy outer layer, allows for penetration)
-all bacteria appear magenta
3.Decolorize with acid alcohol dropwise until smear is decolored, rinse with water (removes stain from non-acid fast cells)
4.counterstain with methylene blue, flood the slide for 2 minutes, the rinse off with water
results: mycobacterium (magenta)
s. epidermis: blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How to create a thin smear?

A
  1. create smear of bacteria on slide
  2. air dry
  3. heat fix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is methylene blue

A

a positively charged, basic stain and will bind to the surface of non-acid fast cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is glycocalyx

A

-is a gelatinous sticky substance surrounding the outside of the cell
-made up of proteins and polysaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

capsule

A

-a glycocalyx that is firmly attached to the cell surface
-this can prevent bacteria from being recognized by the host
-can also camouflage by containing chemicals that are found in the host cell

20
Q

Negative capsule stain

A
  1. use a primary dye such as crystal violet to stain bacteria
  2. stain the background with an acidic negatively charged dye like Nigrosin or India Ink
    Background: India Ink or Nigrosin (pink)
    Bacteria: Crystal violet (purple)
    capsule: clear, colorless, white halo
21
Q

What is the mordant in the Acid-fast staining (Ziehl-Neelson)

A

heat

22
Q

what is the primary stain in Acid-fast staining (Ziehl-Neelson)

A

carbolfuchsin

23
Q

what is the secondary stain in Acid-fast staining (Ziehl-Neelson)

A

methylene blue

24
Q

crystal violet

A

-is positively charged/basic and will stain the negatively charged features on the bacteria besides the capsule

25
Q

Name two negatively charged dyes

A

Nigrosin and India Ink

26
Q

How do negatively charged dyes work?

A

they repel the cell/capsule that is also negatively charged

27
Q

Flagellar staining

A
  • primary stain and mordant are mixed and used as the primary stain
    -this combination allows the dye to be less soluble and coat the surface of the flagella
    -this increases the diameter/size and colorize it so easier to see
28
Q

Monotrichous

A

-one flagella only on one side
ex: vibrio cholerae

29
Q

Amphitrichous

A

-having a single flagellum on each of the two opposite ends
ex: spirillum volutans

30
Q

Lophotrichous

A

multiple flagella at one end or end point
ex: helicobacter pylori

31
Q

Peritrichous

A

having flagella all over, covering the entire surface
ex: Proteus vulgaris

32
Q

Vegetative cell

A

-is the parent cell of an endospore. the vegetative cell breaks open to release the endospores into the environment

33
Q

Why can you not see flagella on smears stained with usual technique?

A

-The flagella are to thin to see without a compound microscope, their width is less than the resolution of microscope

34
Q

Why is heat used to stain bacterial endospores?

A

-heat drives the stain into the cell

35
Q

what are some characteristics of endospores?

A

-endospores are resilient forms of a bacterial cell that forms within the parental cell. They have an impervious cell wall and are resistant to heat/cold, pathogens, toxic changes and desiccation

36
Q

What is the difference between central and terminal endospores?

A

central endospores are located within the middle of the vegetative cell. And terminal endospores are located at the end of vegetative cells.

37
Q

What is meant by the term vegatative cell?

A

-is the parent cell of an endospore, it breaks open to release the endospore into the environment

38
Q

How does the spore stain resemble the acid-fast stain

A

-both the endospore and acid-fast stain require the use of heat to drive the primary stain through the cell wall

39
Q

What pathogen can be presumptively identified using the acid fast stain?

A

mycobacterium species

40
Q

Why can you not see flagella on smears stained within the usual staining technique?

A

-the flagella are too thin to see with a compound microscope

41
Q

What is the principle behind the negative staining technique?

A

-negative stains, stain the entire background surround the cells. A counter stain allows the cells to be visualized and the capsule is left unstained. This leaves a halo like capsule visible between negative and counter stains

42
Q

What structures may be observed with a negative staining technique

A

capsules

43
Q

what stains endospores?

A

malachite green

44
Q

what stains vegetative cells in the endospore stain?

A

safranin

45
Q

what stains the background in the negative stain?

A

India Ink or nigrosin

46
Q

What is the primary stain for acid fast?

A

carbol fuchsin

Microbiology Lab (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions