1. Microscope Basics

2. Parts of the Microscope
1 . Eyepiece : the part that you look through (closest to the eye) usually 10x
2. Objective Lens : the magnifying part closest to the slide (high power=usually 40x; low power=usually 10x)
3. Fine Adjustment Knob : used to focus on low & high power
4. Coarse Adjustment Knob : used to focus only on low power
5. Stage : where the slide is placed
6. Stage Clips : hold the slide in place
7. Diaphragm : controls the amount of light used

3. Calculating Magnification
If a microscope has a 10X eyepiece, and 10X and 40X objectives. Total Magnification on low power : 10 X 10 = 100X ( it looks 100 times bigger than real life) Total magnification on high power : 10 X 40 = 400X (it looks 400 times bigger than real life)

4. Is what we see under a microscope EXACT?
Actual Image
Under microscope F
When we view objects under the microscope…
1. We see a mirror image that is flipped up side down.
2. Increasing magnification reduces the field. (Larger image but you see less of it)
3. Increasing the magnification reduces the amount of light. (Field darkens)

5. How to make a wet mount slide:
Put the cells on the center of a slide, put a drop of water with a dropper onto the cells (do not touch the cells)
Lower a cover slip slowly at an angle (to reduce the number of air bubbles)
Too much water? Use a paper towel to absorb excess liquid.

6. Types of Microscopes: Light microscopes: - Around 1600
The ones that WE use!
Lenses made of glass or plastic
Maximum = 2000x larger

7. Types of Microscopes
Electron Microscopes: View molecules and atoms, smaller images than a light microscope -1st type= Transmission Electron Microscope (TEM) - beams of electrons - resolution = 1000x better than light microscope

8. SEM Scanning Electron Microscope 1935
Better depth of view, higher resolution, more detailed surface picture
resolution: A measure of the clarity of an image; the minimum distance that two points can be separated by and still be distinguished as two separate points.

10. Important Units for Microscopes
Micrometers (microns) = µm
1/1000th of a millimeter
1000 micrometers = 1 mm
How big is a micron? 

11. Finding Field of View (F.O.V)
Under Low Power: Use millimeter ruler
Ex: 1.5mm
Convert to micrometers
1 mm = 1000 micrometers
So 1.5 mm = 1,500 micrometers
(Move decimal over 3 to right)

12. Finding Field of View (F.O.V)
Under Medium or High Power
Need to set up a proportion
Remember!!
As magnification increases FOV decreases
Low power Magnification = High power FOV
High power Magnification Low power FOV
Ex: 100x = HP FOV
500x micrometers
500x =
HP FOV = 300 micrometers

13. Practice:
A student determines that the field of view with a 10 X ocular and a 4 X objective is 2.1 mm in diameter. What is the diameter of the field of view with the same ocular and a 40 X objective?

14. Determining the Size of an Object Under a Microscope
1) View and draw object on low power
2) Estimate how many objects would fit across diameter of field of view
Divide the diameter of FOV by the number of objects that can fit across it.
Ex:
Three letter “e”s fit across FOV of 1800 micrometers
Each letter is about 600 micrometers
1800 micrometers = µm
3 letter “e”

15. Practice:

16. 1. What is the primary difference between a low - power objective and a high - power objective?
2. What is the total magnification of a microscope with a 15 X ocular and a 40 X objective?

17. STUDENT NOTES

18. Microscope Basics

19. Parts of the Microscope
1 . ____________: the part that you look through (closest to the eye) usually 10x
2. _____________Lens : the magnifying part closest to the slide (high power=usually 40x; low power=usually 10x)
3. __________________Knob : used to focus on low & high power
4. _____________Adjustment Knob : used to focus only on low power
5. ____________: where the slide is placed
6. ________________: hold the slide in place
7. __________________: controls the amount of light used

20. Calculating Magnification
If a microscope has a 10X eyepiece, and 10X and 40X objectives. Total Magnification on low power : ( it looks __________times bigger than real life) Total magnification on high power : (it looks 400 times bigger than real life)

21. Is what we see under a microscope EXACT?
Actual Image
Under microscope
When we view objects under the microscope…
1. We see a ________________that is ____________________________.
2. ______________magnification
_________the field. (Larger image but you see less of it)
3. ______________the magnification _____________the amount of light. (Field darkens)

22. How to make a wet mount slide:
Put the cells on the _______________, put a _______________ with a dropper onto the cells (do not touch the cells)
Lower a cover slip ___________________________(to reduce the number of air bubbles)
Too much water?

23. Types of Microscopes: Light microscopes: - Around 1600
The ones that WE use!
Lenses made of glass or plastic
Maximum = 2000x larger

24. Types of Microscopes
Electron Microscopes: View molecules and atoms, smaller images than a light microscope -1st type= Transmission Electron Microscope (TEM) - beams of electrons - resolution = 1000x better than light microscope

25. SEM Scanning Electron Microscope 1935
Better depth of view, higher resolution, more detailed surface picture
resolution: A measure of the clarity of an image; the minimum distance that two points can be separated by and still be distinguished as two separate points.

26. Important Units for Microscopes
Micrometers (microns) = µm
1/1000th of a millimeter
1000 micrometers = 1 mm
How big is a micron? 

27. Finding Field of View (F.O.V)
Under Low Power: Use millimeter ruler
Ex: 1.5mm
Convert to micrometers
1 mm = _______________________
So 1.5 mm = 1,500 micrometers
(Move decimal over _______________)

28. Finding Field of View (F.O.V)
Under Medium or High Power
Need to set up a proportion
Remember!!
As magnification increases FOV decreases
Low power Magnification = High power FOV
High power Magnification Low power FOV
Ex: 100x = HP FOV
500x micrometers
500x =
HP FOV = 300 micrometers

29. Practice:
A student determines that the field of view with a 10 X ocular and a 4 X objective is 2 .1 mm in diameter. What is the diameter of the field of view with the same ocular and a 40 X objective?

30. Determining the Size of an Object Under a Microscope
1) ________and ____________object on low power
2) _____________how many objects would fit across diameter of field of view
Divide the diameter of FOV by the number of objects that can fit across it.
Ex:
Three letter “e”s fit across FOV of 1800 micrometers
Each letter is about 600 micrometers

31. Practice:

32. 1. What is the primary difference between a low - power objective and a high - power objective?
2. What is the total magnification of a microscope with a 15 X ocular and a 40 X objective?