Microscopy Flashcards
1
Q
How do light microscopes work?
A
- Visible light passes through and is bent through the lense system.
- Cells are usually transparent (can be coloured with a stain)
2
Q
How do electron microscopes work?
A
Uses a beam of electrons instead of light
3
Q
What are the two types of electron microscopes?
A
Transmission electron microscopes (TEM)
Scanning electron microscopes (SEM)
4
Q
Transmisssion electron microscopes (TEM)
A
- Beam penetrates the cell, provides details of cells internal structures
- Uses electromagnets to focus electron beams
- High resolution
- Thin specimens
5
Q
Scanning electron microscopes (SEM)
A
- Beam of electrons move back and forth over the cells surface, creating details of cell surfaces characteristics
- Knocks electrons off the surface of the specifmen, these electrons come together to form an image.
- Don’t have to be thin (can be 3 dimensional)
- Lower resolution required than TEM’s
6
Q
Light microscope - Max resolution
A
0.2 micrometres
7
Q
Light microscope - Max magnification
A
around x1500
8
Q
Light microscope - Uses
A
- Study living cells
- When relatively low magnification and resolution is required
9
Q
Electron microscope - Max resolution
A
0.0002 micrometres
10
Q
Electron microscopes - Max magnification
A
Around x1,500,000 (1.5 mil)
11
Q
Electron microscope - Uses
A
Used to investigate the detailed structure of tissues, cells, organelles & macromolecular complexes
12
Q
TEM - Uses
A
- Cancer research
- Virology
- Pollution
- Nanotechnology
13
Q
SEM - Uses
A
- Materials science for research (investigation into nanotubes and nonofibres etc.)
- Quality control & failure analysis
14
Q
Virology
A
Scientific study of viruses
