1. By: Jessie Zaverl and Paneet Saini
ELECTRON MICROSCOPY
By: Jessie Zaverl and Paneet Saini

2. THE ELECTRON MICROSCOPE
-beams of highly energetic electrons are used to create a larger image of a very fine specimen
(usually too small to see with the naked eye)
-used on a fluorescent screen or photographic plate
-images are created by electrons bending and reflecting

3. How it works..
Electrons from the energy source are sent toward the specimen
Electrons are focused by metal apertures and magnetic lenses
Beam of electrons is focused using magnetic lenses
Interactions occur in the sample, affecting the electron beam

4. Transmission Electron Microscope (TEM)
-much like a light microscope
Electrons are used as the “light source”
-sends an electron beam through thin slice of the specimen
The pictures could be recorded by a photographic film

5. TYPES OF IMAGES – (TEM) Mitochondria Lung Leaf from a green plant
Polio Virus
negatively stained Salmonella bacteria.
Bacteriophages

6. Scanning Electron Microscope (SEM)
-The beam of the electrons never carries a clear image
-probes an image on a raster scan by focused electron beams
-Some energy is lost in the beams but that energy is then turned into heat, light emission or
x-ray emissions
-relies on surface dimension
*Used in many medical practices

7. TYPES OF IMAGES- (SEM)
Pollen
Ant
Cat flea
Fruit Fly- compound eye

8. QUESTIONS
Beams of highly energetic electrons produce a _________ image of a very _______ specimen.
smaller; tiny
Larger; fine
Bigger; large
Distinct; large
The Transmission Electron Microscope __________ a beam of electrons
through a thin slice of the specimen while the Scanning Electron Microscope
relies on ______________.
transmits; radiation
Scans; transmission
Transmits; surface dimension
Moves; transmission

9. REFERENCES