| Two types of microscopes | - Optical (light)
- Election |
| Optical (light) microscopes | - Uses light to form image
- Max resolution - 0.2 micrometres
- Can only see mitochondria and nucleus
- Magnification - x1500
- Can be alive specimens |
| Electron microscopes | - Uses electrons to form image
- Higher resolution (electrons have shorter wavelength), Max - 0.0002 micrometres
- Can see more organelles
- Magnification - x1,500,000
- Have to be dead specimens |
| Two types of electron microscopes | - Transmission electron microscopes (TEMs)
- Scanning electron microscopes (SEMs) |
| Transmission electron microscopes (TEMs) | - Uses electromagnets to focus beam of electrons, then transmitted through specimen
- Denser part of the specimen absorb more electrons, makes them look darker |
| Advantages + disadvantages to TEMs | - High resolution images than SEMs
- Can only use thin specimens |
| Scanning electron microscopes (SEMs) | - Scans a beam of electrons across specimen, knocks off electrons, which is gathered in a tube cathode ray tube
- Image shows surface of specimen
- Can be 3D |
| Advantages + disadvantages to SEMs | - They can be used on thick specimens
- Lower resolution images than TEMs |
