Microscopy Flashcards
1
Q
Light microscope
A
A light is passed through the specimen and looked at directly using two lenses:
- 2D
- Poor resolution
- magnification of up to X400 (normal) or X1500 (lab)
2
Q
Types of sample prep
A
- Dry mount
- Wet mount
- Squash slides
- Smear slides
3
Q
Dyes used in gram stain technique
A
- Crystal violet (gram positive turns blue)
- Safranin (gram negative turns red)
4
Q
Dye used in acid fast technique
A
Carbolfuchsin dissolved in lipid solvent (mycobacterium)
5
Q
Eyepiece graticule
A
- Glass disc marked with a scale from 1-100 (no units)
- Relative size of divisions increases with each magnification
- Calibrated using a stage micrometer
6
Q
Stage micrometer
A
- A microscopy slide with a very accurate scale
- 100 division, each 10nm long
7
Q
Transmission electron microscope (TEM)
A
A beam of electrons is transmitted through the specimen and focused to produce an image:
- 2D
- Highest resolution (0.5nm)
- Magnification of up to X1,000,000
8
Q
Scanning electron microscope (SEM)
A
A beam of electrons is sent across the surface, reflected and then collected:
- 3D
- Good resolution (3-10nm)
- Magnification of around X100,000
9
Q
Laser scanning confocal microscope
A
A single spot of focused light is moved across the specimen, causing fluorescence from components labelled with dye:
- 2D or 3D (using multiple scans)
- Better resolution than normal light microscope (0.8nm max)
- Magnification of around X400
