1. Microscope measurement

2. You should know already…
All parts of the microscope.
How to calculate total magnification.
How to make a wet mount.
What an e looks like in the microscope.
Use ONLY the fine adjustment with the…
high power objective.
It’s darker under high power, so you need to adjust the…
diaphragm to let more light in.
The field of view is smaller under…
High Power

3. Lesson Objectives: you should be able to:
Measure the field of view with a ruler.
Estimate the size of a micro-organism.
Convert mm to um.
Calculate the size of the field of view under HIGH POWER.
Practice

4. How do you measure a Paramecium?

5. paramecium

6. paramecium mm

7. Metric system Review Kilo Hecto Deka Meter Deci Centi Milli Liter Grams
100
1 meter = ______ cm
2 cm = ________ mm 20

8. Micrometers
The small size of cells requires another unit called the micrometer.
1 mm = 1000 micrometers (um)

9. 1mm
What if I knew that the diameter of the field of view is 1mm…

10. K H D _ d c m - - µ 1mm 111 millimeter = ________ 1micrometers1
1mm x 1000 = 1000um
K H D _ d c m - - µ

11. 1000 µm
What if I knew that the diameter of the field of view is 1000 um…
Then the paramecium is… _________um
700

12. 100x

13. mm
1.5 mm = um

14. * *
1500 um

15. 500 um * *
1500 um

16. How wide is the Amoeba?
2000 mm
1000 um

17. How wide is the euglena?
4000 mm
2000 um

18. How many could fit across?
4mm 8

19. FOV= 4mm. 8 can fit across.
4mm
4000
500 = 8 8

20. mm
1500 um
25 can fit
1500 um
60 um each 25

21. Find the diameter of the FOV under Low and High Power
2000 um
FOV= __________
FOV= __________

22. 4 times as powerful
2000 um
500 um
FOV= __________
FOV= __________

23. Ex. 1 Microscopic Measurement
Total Low Power Magnification= 4
Total High Power Magnification=
800x
Low Power Field of View= um 4
400 um
High Power Field of View=

24. Ex 2. Micro Measurement 4x Magnification LP = 100x
Magnification HP = 400x
Field of View LP =
Field of View HP = ? ? ? ? ? 4x
4mm =
4000 µm
1000 µm

25. Low Power = 100x High Power = 400x Low Power Diameter = 1600 um High Power Diameter = 400 um
If you can see 12 cells under low power, how many can you see under high power?
12 / 4 = 3

26. Low Power Diameter = 1600 um High Power Diameter = 400 um
If 1 cell could fit across the high power diameter, how big is each one?
If 2 cells could fit across high power, how big is each one?
400 um
200 um

27. Low Power Diameter = 1600 um High Power Diameter = 400 um
If 4 cells could fit across the low power diameter, how big is each one?
If 2 cells could fit across low power, how big is each one?
400 um
800 um

28. Practice 3 : 8 500 µm 500 µm Low Power FOV = 4000 µm
High Power FOV = 1000 µm
500 µm 8
High Power
500 µm

29. stop

30. Microscope Measuring Lab #4
Find the Diameter of your Field of View
Low power and High power
Then Measure:
Corn/Zea/Pith Cells
Paramecium
Stentor
White Fish Embryo

31. Pith Cells/ Corn/ Zea stem
Low Power x
High Power x
FOV= 2000 um
FOV= 500 um

32. Paramecium, Stentor, Embryo

33. Review

34. To locate a specimen on a prepared slide with a compound microscope, a student should begin with the low-power objective rather than the high-power objective because the
field of vision is smaller under low power than under high power
field of vision is larger under low power than under high power
specimen does not need to be stained for observation under low power but must be stained for observation under high power
portion of the specimen that can be observed under low power is less than the portion that can be observed under high power

35. How many micrometers?
2000 um mm
1500 um mm

36. The protist is about
2.5 mm
Or 2500 micrometers
5mm

37. The protist is about
3 mm or
3000 micrometers
9mm

38. The protist is about
1 mm or 1000 micrometers
3mm

39. Micrometers µm If the field of view is 2 mm, how big is the protist?
The field of view is 2000 um
The protist is 1000 um.

40. If you look at the same paramecium under a lower power on the microscope, and follow the same steps, what would you find for the size of the paramecium?
.5 mm
.5 mm
3.0 mm
1.5 mm

41. Before you begin: Directions
Read directions carefully and check them off as you go.
Really…read the directions
Seriously ..read the directions and do exactly as they say.