1. 1.1b Microscopes

2. Types of Microscopes
Simple
Compound
Stereoscopic
Electron

3. Simple Microscope Has only one lens
Functions as a type of magnifying glass
Recall: Robert Hook and his first microscope

4. Simple Microscope

5. Compound Microscope Consists of two or more lenses
Light that travels through this system of lenses allows for the specimen to be seen

6. Stereoscopic Microscope
Allows for objects to be seen in 3-D.
This is due to the arrangement of lenses.
Sometimes this is called the dissecting microscope.

7. Electron Microscope
Uses magnetic field to bend beams of electrons instead of using lenses to bend beams of light.
They have magnifications of up to 10,000,000x compared to a compound microscope which are typically maximum 2000x

8. Electron Microscope
Electron microscope image of a fly foot

9. Parts of a Microscope Eyepiece Body Tube Revolving Nosepiece Arm
Objective Lens
Stage
Stage Clips
Coarse Focus
Diaphragm
Fine Focus
Light
Base

10. Total Magnification x Objective Lens = Total Magnification
Eyepiece lens usually has a power of 10x
Eyepiece Lens x
Objective Lens =
Total Magnification

11. Safety Precautions
We ALWAYS use 2 hands to carry microscopes! They are heavy and require attention when being lifted.
Use extra care when focusing at a high power setting!
Don’t force anything to move if it doesn’t feel like it should.
Only use lens paper for cleaning (if required).
The glass slides are fragile, always handle them with caution.

12. Lab
Purpose:
To become familiar and experiment with using a light microscope.
To investigate structures of the cell using light microscopes.

13. Lab Method Plug in microscope, then proceed to turn it on.
Place the slide of the Elodea leaf cells on the microscope’s viewing platform.
Ensure that the microscope is on the lowest power.
Carefully use the course adjustment knob to focus.
View through the eyepiece.

14. Lab Method When using the highest power objective:
Use extra caution when adjusting using the fine adjustment knob only! Ensure that the lens is NOT touching the slide.
When you have finished with this specimen, turn the objective lenses down to the lowest power, remove the specimen and return it to its designated location.

16. Rules of a Scientific Drawing?
Scientific Drawings must:
Have a title.
Contain the total magnification.
Have proper labels: straight lines, no crossing of lines, with lower case letters only.
Be drawn on the left and labelled on the right side of the paper.
Be drawn on blank paper and in pencil!
Be about 10 cm in diameter.
Not include shading, but a technique that uses a series of dots to emphasize darkness (stippling).

17. Scientific Drawing Guidelines
On a separate sheet of paper..
Complete one scientific drawing of the Elodea Leaf.
Draw only what you see (not what you “think” you should see). Keep your drawing simple and large enough to be clear.
Scientific drawings will be marked accordingly:
Title A
Magnification A
Lines (use of rules, no arrows, no crossing lines, horizontal lines) 3A
Labels (lower case letters, printing) 2A
Stippling (no shading) A
Organelles labeled accurately (at least 4 organelles labeled) 4A
Neatness and accuracy A
Total /15A

18. What is a Scientific Drawing?

19. What is a Scientific Drawing?

20. Elodea Leaf
Elodea leaf 160 X

21. Plant Cells

22. Animal Cells
Human Skin Cells 100X
Human Cheek Cells