Transcript The Scanning Electron Microscope (SEM)

ELECTRON MICROSCOPES
 More powerful; some can
magnify up to 1,000,000X
 Use a magnetic field in a
vacuum to bend beams of
electrons
 Images must be
photographed or produced
electronically
Scanning Electron Microscope (SEM)
Electron microscope image of a spider


produces realistic 3D image
only the surface of
specimen can be observed
Electron microscope image of a fly foot
Transmission Electron Microscope
(TEM)
 produces 2D image of
thinly sliced specimen
 detailed cell parts (only
inside a cell) can be
observed
Scanning Tunneling
 able to show
arrangement of
atoms
Microscope (STM)
Using a Scanning Electron Microscope (SEM)
to see Marine Organisms
We Can Compare Light microscope (LM)
images to various EM micrographs
Human Lung Tissue – LM – 500X
SEM Micrograph of Lung Tissue – 5000X
Lung Tissue using a Transmission EM (TEM)
Sea Urchin Cell Mass - SEM
Sea Urchin Cell – TEM – 50000X
Cholera Bacteria – SEM – each bacterium
is 1 micron (10-6 m)
Cholera Bacteria - TEM
Pancreas Tissue – LM – 1000X
Pancreas Mitochondrion – TEM – 100000X
HIV Attacking a Cell - TEM – 100000X
NOW SEVERAL SEM MICROGRAPHS can you identify what they are??
Deer Fly Antenna Joint
Deer Fly
Head of a June Bug
Head of a Gnat Fly
Head and Tongue of a Moth
Eye of an …….
…… ANT
Skin (Exoskeleton) of a ……….
DUST MITE – on your pillows and in bedsheets
Cross-section of a Walnut leaf
A single grain of Pollen
Many different species of Pollen grains
Clawed food of a Black Widow spider
Foot of a Hornet
Breast Cancer Cell
Mouth of a Human Gut parasite
Common Flea
Velcro – Hooks and Strands – 50X
Staple through paper – 35X
Hypodermic Needle - 35X
Snow Crystal – 200X