lab Flashcards

1
Q

negative stain appearance

A

colorless on dark background

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

negative dyes

A

india ink, congo red, nigrosin

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

part of cell most involved in gram staining

A

peptidoglycan layer

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

The Gram stain is a type of _________ stain because _______is/are used in the procedure.

A

differential, multiple dyes

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

You are preparing a sample to be gram-stained. You have a tube of mixed bacteria, a loop, slides, staining rack, dyes, and a bacticinerator. What’s your next step?

A

heat fix sample to slide

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

how can a sample become contaminated?

A

lack of aseptic technique, leaving tube open for too long, not properly heating inoculation tools

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

sign of bacterial growth in liquid media

A

turbidity (cloudiness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

colony characteristics

A
  • derived from one cell
  • visible to naked eye
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

fermentation possible end products

A

gas, alcohol, acid

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

fermentation type of tube

A

phenol red durham tube

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

fermentation inoculation tool

A

loop for bacteria, needle for yeast

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

fermentation: yellow color

A

acid production
- lower pH

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

fermentation: bubbles

A

gas production

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

fermentation: red color

A

alcohol production

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

triple sugar iron inoculation tool and technique

A

needle
streak surface, stab butt

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

tsi slant makeup

A

1% lactose
1% sucrose
0.1% glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

tsi: yellow butt, red slant

A

glucose only fermented

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

tsi: whole tube yellow

A

glucose and lactose/sucrose fermented

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

tsi: black

A

H2S production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

tsi: whole tube red

A

no fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

tsi: splitting or lifting

A

gas production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

starch hydrolysis: media type

A

enriched differential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

starch hydrolysis: how to observe

A

after incubation, add 10-15 drops gram’s iodine to plate
whole plate will be dark, zones of lighter color around line indicate a-amylase production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

broth to slant tool and technique

A

loop: dip in broth, streak in zig-zag pattern across slant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
broth to broth tool and technique
loop: dip and dip
26
slant to slant tool and technique
needle: take from top, streak slant with needle
27
broth to deep tool and technique
needle: dip, stab into deep
28
sign of bacterial growth in deep
growth along stab line
29
sign of bacterial growth in slant
zig-zag growth pattern
30
spread plate: dilution
take loopful of bacteria and place into sterile saline, mix well
31
spread plate: spread technique
take 0.1 mL of saline mix and spread onto TSA plate using flamed hockey stick
32
streak plate: 4 types of media used
blood agar mannitol salt agar MacConkey agar EMB agar
33
streak plate: mixture and tool used
mix of s.aureus, e.coli, p.vulgaris spread with loop
34
streak plate: mannitol salt agar colony
s. aureus: circular, flat, white selected for on this agar bc it is mannitol +
35
streak plate: blood agar colony
- small white dots, no distinction between species
36
streak plate: EMB agar colony
metallic, green growth (e.coli in this mixture) gram - bacteria
37
streak plate: macconkey agar
pink growthg gram - lactose fermenters
38
kirby-bauer method: negative control
water
39
kirby-bauer method: positive control
10% bleach
40
kirby-bauer method: resistance measurement
zones of inhibition: larger zone = greater resistance
41
IMViC: reaction
tryptophan --tryptophanase--> indole + pyruvate ammonia
42
IMViC: dry slide
- tests for indole production - positive is red
43
IMViC: methyl red/voges-proskauer media and inoculation
MR-VP broth inoculated with looop
44
IMViC: MR-VP transfer
take 1/3 of growth culture into empty sterile tube for VP test, leave 2/3 for MR
45
MR test method and results
add 4-5 drops of methyl red into tube red is positive for acid production mixed acid fermenters
46
IMViC: SIM deep method and results
stab with needle observe for H2S, indole, and motility H2S = black indole = red motility = cloudiness
47
VP test method and results
add 12 drops VP reagent A, 4 drops VP reagent B and vortex red: acetoin positive yellow: acetoin negative
48
citrate test: method and results
streak and stab with needle green = citrate - blue = citrate +
49
casein hydrolysis: plate preparation
mix agar with skim milk and let solidify
50
casein hydrolysis: inoculation
use loop to draw circle in each triad
51
casein hydrolysis: analysis
measure zones of proteolysis
52
catalase activity: method
use a sterile cotton swab to place bacteria on glass slide add 1-2 drops H2O2 to slide and watch for bubbles (O2 production)
53
what does VP test for?
glucose fermenters: produce 2,3-butanediol and acetoin
54
In the streak plate method, which quadrant should contain the most bacterial growth?
quadrant 1
55
fermentation
- biochemical rxn that produces energy under anaerobic conditions - organic molecules = electron donors - organic intermediates = electron acceptors
56
durham tube
traps gas
57
The TSI test must be incubated for a specific time period of
18-24 hours
58
casein hydrolysis: positive results
bacteria that secrete proteolytic enzymes
59
The enzyme catalase catalyzes the decomposition of __________ to ________ and _______.
h2o2; h2o; o2
60
bacteria can convert NO3 into
NO2, N2, NH3
61
Nitrate reagents A and B detect the presence of
NO2
62
Upon the addition of nitrate reagent C, the control tube should turn
red