2. Types of microscope

3. Electron Microscope

4. An electron microscope

5. Magnification = The number of times the image has been enlarged by the microscope, bigger than the object’s real actual size. The number of times the image has been enlarged by the microscope, bigger than the object’s real actual size. LM max mag. = 1,500X, EM max mag. 500,000X Resolution (or Resolving power) = The ability of the microscope to distinguish clearly between 2 points that are extremely close together.

6. Figure 1.1 Magnification vs. Resolution

7. Resolution The Light Microscope has a resolving power of around 250nm (nanometers) which is the same as 0.25μm (micrometers), so if two objects are closer than 0.25μm they will not be detected as 2 clear points. The Light Microscope has a resolving power of around 250nm (nanometers) which is the same as 0.25μm (micrometers), so if two objects are closer than 0.25μm they will not be detected as 2 clear points. The Electron Microscope has much better resolving power of around 1nm, which is the same as 0.001μm, so it can detect much greater detail. The Electron Microscope has much better resolving power of around 1nm, which is the same as 0.001μm, so it can detect much greater detail.

8. See my pdf notes comparing wavelenths of light and an electron beam See my pdf notes comparing wavelenths of light and an electron beam

9. There are 2 different types of Electron Microscope:

10. Transmission electron microscope A transmission electron microscope produces 2D images from electrons which pass through the sample. An extremely thin specimen is needed. A transmission electron microscope produces 2D images from electrons which pass through the sample. An extremely thin specimen is needed.

11. Golgi body surrounded by mitochondria in a mouse myeloid cell Golgi body surrounded by mitochondria in a mouse myeloid cell

12. A plant cell A plant cell

13. Scanning Electron Microscope A scanning electron microscope produces 3D images from electrons reflected off the sample’s surface.

14. Isolated mitochondria from bovine lymphocytes Isolated mitochondria from bovine lymphocytes

15. Philonicus albiceps head Philonicus albiceps head

16. This cell is a type of skin cancer cell. The cell has been frozen and split open to reveal its nucleus (central red area). (Image: Anne Weston)

17. What next? Complete the comparison tables on the bottom of your Handbook p4 and the top of p5 booklet by circling the correct choices and crossing out the wrong ones - use textbook pages 43-45 to help. Complete the comparison tables on the bottom of your Handbook p4 and the top of p5 booklet by circling the correct choices and crossing out the wrong ones - use textbook pages 43-45 to help. Now complete tasks found in the middle of handbook p5. Now complete tasks found in the middle of handbook p5.

18. Units of measurement 1m (1 metre) = 1000mm 1m (1 metre) = 1000mm 1mm = 1000µm (micrometres) 1mm = 1000µm (micrometres) 1 µm = 1000 nm (nanometres) 1 µm = 1000 nm (nanometres) To convert mm to µm multiply by 1000 To convert mm to µm multiply by 1000 To convert µm to mm divide by 1000 To convert µm to mm divide by 1000 When doing calculations you need to make sure that your measurements are in the same units. When doing calculations you need to make sure that your measurements are in the same units.