Question

Compare and contrast a compound light microscope and a transmission electron microscope. Be sure to discuss the structure and operation of each, as well as the function and usefulness of each when examining specimens.

Answer 1

Compound light microscope - Microscope with more than one lens and its own light source. There are ocular lenses in the bonicular eyepieces and objective lenses in a rotating nosepiece closer to the specimen.
To ascertain the power of magnification of a compund light microscope, it's needed to take the power of the objective lens and multiply it by the eyepiece which is generally 10x.
Although sometimes found as monocular with one ocular lens, the compound binocular microscope is more commonly used today.
The first light microscope dates back to 1595, when Zacharias Jansen created a compound microscope that used collapsing tubes and produced magnifications up to 9X.

Answer 2

Transmission electron microscope - The transmission electron microscope (TEM) operates on the same basic principles as the light microscope but uses electrons instead of light. What you can see with a light microscope is limited by the wavelength of light. TEMs use electrons as "light source" and their much lower wavelength makes it possible to get a resolution a thousand times better than with a light microscope.
The possibility for high magnifications has made the TEM a valuable tool in both medical, biological and materials research.

Answer 3

As far as usefulness goes, compound microscopes are MUCH less expensive and so can be purchased on most research budgets. They run maybe between USD 200 and 1000. Transmission EM scopes run about $2,000,000 for a decent one. EMs are also more expensive to operate: they require special rooms, and it can be very expensive to produce the electron beam.

Of course, the resolution is much higher. Compound microscopes are limited by the wavelength of light (max about 2000x), whereas EM can magnify specimens up to about 500,000x. This is a huge advantage of using EM, especially if you need to resolve tiny objects or structures in your specimen.

However, unlike EM, light microscopes can look at live specimens. So, if your work requires the microscopic views of living organisms, the EM is completely useless. Light microscopes also produce color image: the micrographs from EMs are black-and-white. If you need to see color, you can't use EM.

Finally, your specimen is destroyed after the lengthy prep and viewing in an electron microscope. The material in light microscopy doesn't have to be destroyed, but the use of special stains may be necessary to see cells or cell structures.

Answer 4

Compound light microscope: Light illuminated. Two dimensional images. This microscope is the most commonly used. You can view individual cells, even living ones. High magnification, but a low resolution. Specimens are placed on glass slides and are seen through light absorption.

Transmission electron microscope: Electron illuminated. Has a 2-D view. Thin slices of specimen are obtained. The electron beams pass through it and seen by means of electron scattering. It has high magnification and high resolution. Specimens are mounted on thin films of collodion or other supporting material on copper grids.

Source: http://www.cas.muohio.edu/mbi-ws/microscopes/types.html

Answer 5

*All sources from Internet ;) Hope it helps

Answer 6

Thank You !!