Microscopes Compound Light Microscope Electron Microscopes (TEM and SEM)
By: Rob Page and Tara Trovarello. Light Microscope The Light microscopes are a simple microscope...
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Transcript of By: Rob Page and Tara Trovarello. Light Microscope The Light microscopes are a simple microscope...
By: Rob Page and Tara Trovarello
Light Microscope The Light microscopes are a
simple microscope that uses only one lens for magnification.
Light Microscopes can view specimens in color
An important, useful advantage over the electron microscope.
The first microscope was invented by Hans and Zacharias Janssen in 1590.
Components of a Light Microscope 1- The Ocular Lens, or also
the Eyepiece 2- Objective Turret 3- Objective Lenses 4- Coarse adjustment knob 5- Fine adjustment knob 6- Object holder, or Stage 7- Mirror, or Light 8- Diaphragm and Condenser
Different types of Light Microscopes Bright-field microscope Dark-field Microscope Phase-contrast microscope Differential-interference-
contrast microscope Fluorescence microscope Confocal microscope
Bright-Field microscope It is the simplest of all the
optical microscopy illumination techniques.
Simplicity of setup with only basic equipment required.
No sample preparation required, allows to view living cells.
Light is simply transmitted through a specimen, giving little contrast.
Staining specimens improves contrast but required that cells be fixed (not alive), which can cause distortion or alternation of components
Dark-field microscope Light is directed at an angle
toward the specimen. A condenser lens transmits
only light reflected off the specimen.
The field is dark, and the specimen is light against this dark background.
Phase-contrast microscopeComponents of the
microscope bring light waves out of phase, which produces differences in contrast and brightness when the light waves recombine.
Differential-interference contrast microscopeOut-of-phase light
waves to produce differences in contrast and brightness are combined with two beams of light traveling close together, which create even more contrast, especially at the edges of structures.
Fluorescent microscopeFluorescent stains
absorb light at one wavelength, then emit it at another.
Filters transmit only the emitted light.
Confocal microscopeLight from a laser is
focused to a point and scanned across the fluorescently stained specimen in two directions.
Clear images of one plane of the specimen are produced, while other planes of the specimen are excluded and do not blur the image.
Multiple planes can be used to reconstruct a 3-D image.
Works Citedwww.google.images www.google.com www.wikipedia.org Textbook