The Discovery of Cells The invention of the microscope made it possible for scientists to view and study cells. Cells the basic units of all living organisms.
The Cell Theory All living things are made of one or more cells. Cells are the basic units of structure and function in living things. All cells come from other cells.
Microscopes help scientists learn more about cells. It is an instrument used to see objects that are too small for the unaided eye.
1. head the part that holds the eyepiece tube and lens can sometimes be rotated to easily share your view with others
2. Arm supports the eyepiece and connects it to the base
3. Coarse Adjustment Knob moves stage up and down
4. Fine Adjustment Knob small, round knob on the side of the microscope used to fine-tune the focus of your specimen after using the coarse adjustment knob
5. Base the bottom of the microscope, used for support
6. Eyepiece / Ocular Lens magnifies; where you look through to see the image of your specimen. Usually 10x or 15x power. Our microscopes have an ocular lens power of 10x.
7. Objective Lenses Adds to the magnification Usually you will find 3 or 4 objective lenses on a microscope. almost always consist of 4X, 10X, 40X and 100X powers. Ours are 4X, 10X, and 40X
What s my power? To calculate the power of magnification, multiply the power of the ocular lens by the power of the objective. What are the powers of magnification for each of the objective lenses we have on our microscopes?
Magnification Your microscope has 3 magnifications: Scanning (4x), Low (10x) and High (40x). Each objective will have written the magnification. In addition to this, the ocular lens (eyepiece) has a magnification (10x). The total magnification is the ocular x objective
Comparing Powers of Magnification We can see better details with higher the powers of magnification, but we cannot see as much of the image. Which of these images would be viewed at a higher power of magnification?
8. Stage the flat platform where you place your slides
9. Stage Clip holds the slides in place
10. Light / Illuminator makes the specimen easier to see
Microscope Care Always carry with 2 hands! Never touch the lenses with your fingers. Do not force knobs! When you are finished with your "scope : rotate the nosepiece so that it's on the low power objective roll the stage down to lowest level unplug and wrap the cord replace the dust cover.
How to make a wet-mount slide 1 Get a clean slide and coverslip from your teacher. 2 Put your specimen in the center and place ONE drop of water on it, in the middle of the slide. Don t use too much or the water will run off the edge. 3 Place the edge of the cover slip on one side of the water. 4 - Slowly lower the cover slip on top of the drop. Cover Slip Lower slowly 5 Place the slide on the stage and view it first with the red-banded (4x) objective. Once you see the image, you can view the slide with the different objectives (10x, 40x).
Drawing Specimens 1. Use pencil - you can erase and shade areas 2. All drawings should include clear and proper labels (and be large enough to view details). Drawings should be labeled with the specimen name and magnification. 3. Labels should be written on the outside of the circle. The circle indicates the viewing field as seen through the eyepiece, specimens should be drawn to scale - ie..if your specimen takes up the whole viewing field, make sure your drawing reflects that.
Let s give it a try... 1 Turn on the microscope and then rotate the nosepiece to click the red-banded (4x) objective into place. 2 Place a slide on the stage and secure it using the stage clips. Use the coarse adjustment knob (large knob) to get it the image into view and then use the fine adjustment knob (small knob) to make it clearer. 3 Once you have the image in view, rotate the nosepiece to view it under different powers. Draw what you see on your worksheet! Be careful with the largest objective! Sometimes there is not enough room and you will not be able to use it! 4 When you are done, turn off the microscope and put away the slides you used.