1. Incredible World of Microscopes
Read pages
Review / Relearn the parts of the microscope and what their functions are. (handout)
Review / Relearn the correct way to handle the microscope.
Incredible World of Microscopes
Video (22)

2. Revolving Nosepiece (rotates objectives)
Eyepiece (10x)
Revolving Nosepiece (rotates objectives)
“click” to be in place
Objectives (4x, 10x, 40x, 100x)
Stage
Light
Diaphragm (controls amount of light)
Base

3. Arm
Coarse Adjustment (use on low only)
Slide Movers
Fine (focus) Adjustment

4. Stage clips (holds slide in place)
Revolving Nosepiece
Objectives
Stage clips (holds slide in place)
Center of stage (light comes through)

5. Securely fitted Specimen over aperture

6. It should NOT look like this!

7. Diaphragm Slide Movers
(slides to control how much light enters the stage)
Slide Movers
(moves front to back, side to side)

8. Basic Procedure to focus on a specimen:
The microscope should be on LOW power (40x).
Separate the LOW objective and the stage as much as possible so you can see where you are putting the slide.
Roll the COARSE adjustment knob UP until the stage is as close as you can get it to the LOW objective.
Look through the eyepiece and slowly roll the COARSE adjustment knob down to bring the object into focus - the stage should move away from the LOW power. If you turn it more the ½ a turn, you’ve gone too far. Start over.

9. Once you bring the specimen into view on LOW power, use the FINE adjustment knob to bring it into focus.
When you have the specimen in focus on LOW power, rotate the revolving nosepiece to MEDIUM power (100x) – it should “CLICK” into place.
Now you can use the fine adjustment knob to focus – on the higher power -do NOT use the coarse adjustment knob again.
If necessary, rotate to HIGH power (400X, 1000x) and focus with the fine adjustment knob.
Microscopes are designed so when you have the specimen in perfect focus on low power, it will be almost in perfect focus on medium and high. That is why you should only need to use the fine adjustment knob.

10. Always write the Total magnification on the object you are looking at.
Each objective has a different magnification (4x, 10x, 40x)
To determine TOTAL magnification of the specimen you are observing, you must multiply the eyepiece X objective.
10 x (eyepiece) x 4x (low power) = 40x total magnification
10 x (eyepiece) x 10x (medium power) = 100x total magnification
10 x (eyepiece) x 40x (high power) = 400x total magnification
10 x (eyepiece) x 100x (high power) = 1000x total magnification
Always write the Total magnification on the object you are looking at.

11. Field of Vision
Have an idea where the object you are wanting to look at is on the slide.
Place the slide /object / specimen over the light in the center of the stage.

12. Only use the fine adjustment knob now to bring the object into focus.
Once the object is focused on low power, rotate the revolving nosepiece till it clicks the next objective into place.
Only use the fine adjustment knob now to bring the object into focus.
(If you lose it, go back to low power and start over!)
The field of vision will become a smaller area. Make sure your object is in the center of the field of vision.
40x
100x

13. Low = 40x Medium = 100x High = 400x Highest = 1000x
Not everything should be looked at on high power.

14. Odds and Ends:
Do not touch the ends of the objectives (everything you look at will have fingerprints on it).
Always clean any lens of the microscope with lens paper.
Adjust the diaphragm under the microscope to allow the correct amount of light through the stage. Some specimens need a lot of light, some need a little.

15. Always store the microscope on low power (4x), with the cord wrapped around the base and the dust cover on it.
QUIZ TIME!
Video review (5)

16. Wet mount slide preparation.
Put the edge of the cover slip along the liquid and slowly lower toward the slide. You want to push out the air bubbles.
Air bubbles

17. Movement of substances into and out of cells.Pg
Diffusion: mixing of 2(+) substances by random motion of molecules.
high concentration low concentration
* Diffusion will stop when the molecules are evenly spread out.
Ex. perfume, smoke
Osmosis: the diffusion of water across a semi permeable membrane (ex. cell membrane)
water, food, O2
water, waste