2. Microscopes

3. Anton Van Leeuwenhoek
found that by placing glass lenses (lenses refract light) at certain distances from each other, he could enlarge objects in his field of vision
Invented the 1st microscope (light microscope)

4. Leeuwenhoek developed what is called a simple microscope since it had only one lens. We mostly use compound microscopes since they have more than one lens.

5. Important Microscopy Terms
Magnification
Resolving Power
the comparison of the real size of a specimen with that of the one viewed under the microscope
a.k.a. resolution refers to the clarity of the specimen viewed under the scope
Image of pollen grain with good resolution (left) and poor resolution (right)

6. Parts of a Compound Light Microscope

7. Coarse focus adjustment knob
Focuses the image under low power
Usually the bigger knob
Makes larger adjustments

8. Fine focus adjustment knob
Sharpens the image under all powers Usually the smaller knob
Fine Adjustment Knob

9. Arm
Supports the body tube and is used to carry the microscope
Arm

10. Body Tube
Connects the eyepiece to the nosepiece Usually moves during focusing
Body Tube

11. Eyepiece The lens you look through Usually at 10X magnification

12. Nosepiece
a.k.a. revolving nosepiece holds all the objectives and it revolves
Nosepiece

13. Base
Supports the microscope and used for carrying the microscope
Base

14. Stage
Used to support the slide
Stage

15. Stage Clips
Used to hold the slide in place
Stage Clips

16. Diaphragm
Used to regulate the amount of light
Diaphragm

17. Light Source
Provides light
Light Source

18. Low Power Objective
Has the lowest magnification and is the shortest objective
Low power objective

19. Medium Power Objective
increases the magnification
Medium Power Objective

20. High Power Objective
Provides the most magnification and is the longest objective.
High Power Objective

21. Calculating magnification
Determine the magnification of the eyepiece (ocular lens) and each objective.
Multiply the magnification of the eyepiece with the magnification of the objective you are using.

22. Example
Calculate the magnification of a microscope with an eyepiece magnification of 10 and objective magnification is 30.
Answer: 10 X 30 = 300

24. Objectives of Microscope Lab
To learn the parts of the microscope. To find specimens using low and high power. To make a wet mount. To view your own human cheek cells under the microscope.

25. Microscope Care
Always carry with 2 hands
Only use lens paper for cleaning
Do not force knobs
Keep objects clear of desk and cords

26. Microscope Parts Eyepiece Body Tube Revolving Nosepiece Arm
Objective Lens
Stage
Stage Clips
Coarse Focus
This is the exact version of the microscope used in class. Students will be identifying the parts on the microscopes at their desks as we go along and what their functions are.
Diaphragm
Fine Focus
Light
Base

27. Using the Microscope Place the Slide on the Microscope Use Stage Clips
Click Nosepiece to the lowest (shortest) setting
Look into the Eyepiece
Use the Coarse Focus
Give students a slide from the “common things” set, each student will practice focusing and changing objectives.

28. Using High Power
Follow steps to first focus using low power Click the nosepiece to the longest objective Do NOT use the Coarse Focusing Knob Instead use the Fine Focus Knob to bring the slide into view
Have students exchange slides so they can look at different things, walk them through using the high power objective to focus slides. Emphasize not using the coarse objective during this process, as it will crack the slides.
What can you find on your slide?