Microscopes Your ticket to a tiny world!

History of Microscopes– Robert Hooke wasn’t the first to make a

microscope, but he was one of the firsts to use it to make a major discovery about the microscopic world that was previously unseen.

– He discover cells – but you’ll learn more about that in the next un

– Joseph Lister created clearer and stronger lenses that helped scientists discover germs.

– Louis Pasteur was then able to develop a way to kill bacteria in milk by heating it (pasteurization).

What Is a Microscope?

• Microscope is the combination of two words; "micro" meaning small and "scope" meaning view.

Different Kinds of Microscopes

• Simple Microscopes: (the first ones invented) had only one lens.

• Compound Light Microscope: Compound deals with the microscope having more than one lens. The term light refers to the method by which light transmits the image to your eye.

Electron MicroscopesScanning Electron Microscope: SEM use

electron illumination. The image is seen in 3-D. It has high magnification and high resolution. The specimen is coated in gold and the electrons bounce off to give you and exterior view of the specimen. The pictures are in black and white.

• Transmission Electron Microscope: TEM is electron illuminated. This gives a 2-D view. Thin slices of specimen are obtained. The electron beams pass through this. It has high magnification and high resolution

• Scanning Tunneling Electron Microscope:

So powerful it can capture the image of a single atom! The tip of the microscope is only a few atoms wide (very sharp) and measures changes in the electrical forces from the surface of a molecule or atom. It can also be used to move atoms around!

Just How Small Can We Get?

How Does it Work?

Quiz Questions

1. How should you carry your microscope?

2. What power do you always start with?

3. How do you adjust the amount of light?

3. Is it OK to have the lens touching the microscope slide?

4. How do you change from one magnification to another?

5. What holds the slide in place?

6. Describe how a light microscope works (use drawings to help make your explanation clear).

7. What microscope would you use if you wanted to see the shape of a molecule?