Welcome to the World of Microscopes!

Microscope Word Dissection Micro=Small Scope=to look Microscope- An instrument used to see objects too small to be seen by the naked eye.

A Brief History Thought to be the first developer of the compound microscope in 1595. A compound microscope uses two lenses to view an object. Janssen was so young (only 15) that it is believed his father helped him. His microscope consisted of a tube with a lens at both ends. The microscope could magnify from 3 times to 9 times.

Next came Robert Hooke Hooke was a multi-talented scientist and is credited with work in physics, astronomy, biology, chemistry, geology, architecture, and naval technology. Developed an improved version of the compound microscope and published Micrographia in 1665. This document coined the word “cell” to describe the “boxes he saw in cork”.

Followed by Van Leeuwenhoek… Leeuwenhoek worked with simple microscopes, that is, a microscope that had only 1 lens to view an object. The quality of his scope allowed him to be the first to see bacteria and tiny animals in a drop of water called protozoa. Leeuwenhoek worked at the same time as Hooke.

Important Microscope Terms Magnification —How much an image is enlarged.

Resolution—The amount of detail that you can see in an image Resolution—The amount of detail that you can see in an image. Electron microscopes have the best resolution followed by the compound microscope and dissecting scopes.

Depth of Field— The area in front and behind the specimen that is in focus. Depth of field is greater with the scanner lens and lowest with the high power lens.

Field of View— The area that is visible through the microscope Field of View— The area that is visible through the microscope. Field of view is greatest with the scanner lens and worst with the high power lens. Center

What about today? Electron microscopes use electrons to bounce off the object providing the image. Can magnify objects up to 1 million times Will not work on living things because the microscope needs to work in a vacuum.

Care and Feeding Always carry a microscope with one hand under the base and one hand on the arm. The cord should be wrapped around the scope and not be dragging along the ground. Start with the stage in the lowest position and the scanner lens in place. Clean lenses with filter paper ONLY. Unplug your microscope when done using it!

How to Focus Put scanner lens into position. Place slide on stage under stage clips. Make sure your image is centered. Use the coarse adjustment knob to get your image in focus. Use the fine adjustment knob to “tweak” the focus. Adjust the amount of light using the diaphragm to maximize your image quality.

Make sure your specimen is in the exact center of your field of view. Switch to the low power lens. You should see a blurry image of your object. Focus by using the coarse adjustment knob. You should not need to turn this knob very much. Now use the fine adjustment knob and adjust the diaphragm.

Make sure your specimen is in the exact center of your field of view. Now switch to the high power lens. Focus your image using only the fine adjustment knob. Adjust the diaphragm if needed. Very important!!

Making a Wet-Mount Slide Be sure your slide is clean and dry. Place one or two drops of water in the center of the slide. Place specimen in the center of the drop of water. Lower the cover slip over the drop of water and the specimen as if you are closing a door. Absorb any excess water with a small piece of paper towel.

Making Quality Drawings All drawings must be done in pencil. Colored pencils should be used when appropriate. Drawings should be labeled as follows: Title Magnification Labels of important parts Paramecium 100x flagella nucleus

Now let’s get started!!!