Ch. 2: How We See The Invisible World Flashcards
(133 cards)
1
Q
purpose of brightfield microscope
A
Used in wide variety of lab applications as standard microscope
2
Q
Purpose of dark field microscope
A
- increases contrast w/out staining
- useful for viewing live specimens
3
Q
Type of image produced by brightfield microscope
A
produces image on bright background
4
Q
Example of bacteria visualized by brightfield microscope
A
Bacillus sp. showing endospores
5
Q
Image produced by darkfield microscope
A
produce bright image on dark background
6
Q
Example of bacteria visualized by darkfield microscope
A
Borrelia burgdorferi
7
Q
Purpose of phase contrast microscope
A
- uses refraction & interference caused by structures in specimen to create high contrast, high res images w/out staining
- useful for viewing live specimens, structures such as endospore & organelles
8
Q
Image produced by phase contrast microscope
A
uses refraction & interference caused by structures in specimen to create high contrast, high res images w/out staining
9
Q
Example of bacteria visualized with phase contrast microscope
A
Pseudomonas sp.
10
Q
Purpose of differential interference contrast (DIC) microscope
A
- uses interference patterns to enhance contrast between different features of a specimen
- useful in distinguishing structures within live, unstained specimen
11
Q
Image produced by differential interference contrast (DIC) microscope
A
- high contrast image of living organisms with a 3D appearance
- images viewed reveal detailed structures within cells
12
Q
Example of bacteria visualized by differential interference contrast (DIC) microscope
A
E. coli O157:H7
13
Q
Purpose of fluorescence microscope
A
- uses fluorescent stains to produce an image
- can be used to identify pathogens, find particular species, distinguish from dead cells, find locations of particular molecules within a cell
14
Q
Image produced by fluorescence microscope
A
15
Q
Example of bacteria visualized by fluorescence microscope
A
P. putida stained with fluorescent dyes to visualize the capsule
16
Q
Purpose of confocal microscope
A
- scan multiple z-planes successively
- useful for examining thick specimens such as biofilms
17
Q
Image produced by confocal microscope
A
produce numerous 2D high res images at various depths that can be constructed into 3D image by a computer
18
Q
Example of bacteria visualized by confocal microscope
A
E. coli stained with acridine orange due to show nucleoid region of cells
19
Q
Purpose of two-photon microscope
A
- use scanning technique, fluorochromes, & long wavelength light
- penetrates deep into thick specimens such as biofilms
20
Q
Image produced by two-photon microscope
A
21
Q
Example of bacteria visualized by two-photon microscope
A
mouse intestine cells stained with fluorescent dyes
22
Q
Purpose of transmission electron microscope (TEM)
A
- uses electron beams that pass through specimen to visualize small images
- useful to observe small, thin specimens such as tissue sections & subcellular structures
23
Q
Image produced by transmission electron microscope (TEM)
A
24
Q
Example of bacteria visualized by transmission electron microscope (TEM)
A
ebola virus
25
Purpose of scanning electron microscope (SEM)
- uses electron beam to visualize surfaces
- useful to observe 3D surface details of a specimen
26
Image produced by scanning electron microscope (SEM)
27
Example of bacteria visualized by scanning electron microscope (SEM)
*Campylobactor jejuni*
28
Purpose of scanning tunneling microscope (STM)
29
Image produced by scanning tunneling microscope (STM)
30
Example of bacteria visualized by scanning tunneling microscope (STM)
31
Purpose of atomic force microscope (AFM)
32
Image produced by atomic force microscope (AFM)
33
Example of bacteria visualized by atomic force microscope (AFM)
34
Basic stain examples
- methylene blue
- crystal violet
- malachite green
- basic fuchsin
- carbolfuchsin
- safranin
35
Basic stain purposes
stain negatively charged structures & molecules such as nucleic acids & proteins
36
Basic stain outcome
Positive stain
37
Acidic stain examples
- eosin
- acid fuchsin
- rose bengal
- congo red
38
Acidic stain purposes
stain positively charged molecules & structures such as proteins
39
Acidic stain outcome
Can be either positive or negative stain depending on cell’s chemistry
40
Negative stain examples
- india ink
- nigrosin
41
Negative stain purpose
stains background, not specimen
42
Negative stain outcome
Dark background with light specimen
43
Gram stain dyes
- crystal violet
- Gram's iodine
- ethanol (decolorizer)
- safranin
44
Gram stain purpose
used to distinguish cells by cell-wall type (gram-negative, gram positive)
45
Gram stain outcome
- Gram-positive cells stain purple/violet
- Gram-negative cells stain pink
46
Acid-fast stain dyes
- after staining w/basic fuchsin, acid-fast abcteria resist decolorization by acid-alcohol
- non acid-fast bacteria are counterstained w/methylene blue
47
Acid-fast stain purpose
used to distinguish between acid-fast bacteria, such as *M. tuberculosis*, from non acid-fast cells
48
Acid-fast stain outcome
- acid-fast bacteria are red
- non acid-fast bacteria cells are blue
49
Endospore stain dyes
uses heat to stain endospores w/malachite green (Schaeffer-Fulton procedure), then cell is washed & counterstained w/safranin
50
Endospore stain purpose
- used to distinguish organisms w/endospores from those w/out
- used to study endospores
51
Endospore stain outcome
- endospores appear bluish-green
- other structures appear pink to red
52
Flagella stain dyes
flagella are coated w/a tannic acid or potassium alum mordant, then stained using either pararosaline or basic fuchsin
53
Flagella stain purpose
used to view & study flagella in bacteria that have them
54
Flagella stain outcome
flagella are visible if present
55
Capsule stain dyes
- negative staining w/India ink or nigrosin is used to stain the background, leaving a clear area of the cell & the capsule
- counterstaining can be used to stain the cell while leaving the capsule clear
56
Capsule stain purpose
used to distinguish cells w/capsules from those w/out
57
Capsule stain outcome
capsules appear clear or a halos if present
58
Wavelength
distance between one peak of a wave and the next peak of another wave
59
amplitude
height of each peak or depth of each trough
60
frequency
the rate of vibration of the wave or # of wavelengths in a specific time period
61
reflection
occurs when a wave bounces off of a material
62
absorbance
occurs when a material captures the energy of a light wave
63
transmittance
the process of transmission
- transmission occurs when a wave travels through a material
64
interference
65
diffraction
light waves interact w/small objects or openings by bending or scattering
66
refraction
occurs when light waves change direction as they enter a new medium
67
refractive index
the extent to which a material slows transmission speed relative to empty space
68
image point (focus)
69
focal point
the image point when light entering the lens is parallel
70
focal length
the distance to the focal point
71
dispersion
when white light passes through a prism and different colors are refracted in different directions creating rainbow like spectrum
72
fluorescent dyes
absorb ultraviolet or blue light and then use the energy to emit photons of a different color, giving off light rather than simply vibrating
73
phosphorescence
photons may be emitted following a delay after absorption
74
magnification
the ability of a lens to enlarge the image of an object when compared to the real object
75
resolution
the ability to tell that 2 separate points or objects are separate
76
numerical aperture
a measure of a lens's ability to gather light
- higher aperture = better resolution
77
compound microscope
78
simple microscope
79
brightfield microscope
- most commonly used microscope
- compound microscope w/2 or more lenses that produce dark image on bright background
80
monocular
81
binocular
82
ocular lens
83
objective lens
84
total magnification
85
stage
86
x-y mechanical knobs
87
coarse focus knob
88
fine focus knob
89
illuminator
90
condenser lens
91
diaphragm
92
rheostat
93
chromophores
94
oil immersion lens
95
darkfield microscope
96
phase-contrast microscope
97
differential interference contrast (DIC) microscope
98
fluorescence microscope
99
fluorochromes
100
immunofluorescence
101
confocal microscope
102
photon microscope
103
electron microscope (EM)
104
transmission electron microscope (TEM)
105
scanning electron microscope (SEM)
106
scanning probe microscope
107
scanning tunneling microscope (STM)
108
atomic force microscope (AFM)
109
quantum tunneling
110
wet mount
111
fixation
112
smear
113
staining
114
basic dye
115
acidic dye
116
positive stain
117
negative stain
118
simple staining
119
differential staining
120
gram stain procedure
121
primary stain
122
mordant
123
decolorizing agent
124
counterstain
125
acid-fast stain
126
Zehl-Neelsen technique
127
Kinyoun technique
128
capsule staining
129
endospore staining
130
flagella staining
131
transparency
132
opacity
133
contrast
