Microscopes are devices used to magnify biological specimens. There are two main types: compound microscopes, which use light and have objective and eye piece lenses, and electron microscopes, which have much higher resolution and magnification by using beams of electrons. Electron microscopes can be transmission electron microscopes, which show internal structure in detail, or scanning electron microscopes, which provide surface views of specimens.

1. Microscopes

2. Microscope
•Device used to magnify biological
specimen

3. Types of microscopes
Compound
• Use light to show image
• Have 2 lenses
(objective lenses and
eye piece)
Electron
• Resolution is much
better
• Magnification is much
better
• Uses beams of
electrons to view image

4. Magnification
•The magnifying power of the eyepiece
leans x objective lenses
•E.g. 5x10=50

5. • Lenses ~ magnification
• Stage ~ to place the slide on
• Clips ~ hold the slide in place
• Condenser ~ to focus the light on the slide
• Diaphragm ~ to control the amount of light
• Coarse focus knob ~ to roughly focus the image
• Fine focus knob ~ to precisely focus the image
• Light/ mirror ~ to supply light to the object

6. Types of electron
microscope
•1. transmission electron microscope (TEM)
Shows the internal structure of specimen in
great detail
•2. scanning electron microscope (SEM)
Provides a surface view of specimen