Electron Microscope
|
Light Microscope
|
Illuminating source is beam of electrons. | Illuminating source is light. |
It is very large and complicated. | Microscope is compact and handy. |
Only fixed specimens are studied. | Both living and fixed specimens can be studied. |
The object is ultrathin, 0.1µm or below. | The object is 5 µm or thicker. |
Only dehydrated specimens are used. | The specimen need not be dehydrated. |
Vacuum is essential for its operation. | A vacuum is not required. |
High voltage electric current is required(50,000 volts and above). | There is no need for high voltage electricity. |
Tungsten filament is used to produce electrons. | A filament is not used. |
It has a cooling system to take out heat generated by high voltage electric current. | There is no cooling system. |
There is risk of radiation leakage. | Radiation risk is absent. |
It employs elecromagnets. | Light microscope uses glass lenses. |
Image is formed due to scattering of electrons.  | Image is formed due to absorption of light waves.  |
Image is seen only on a fluorescent screen. | Image can be seen directly. |
Specimen is coated with heavy metals in order to reflect electrons. | Specimen is stained by coloured dyes. |
Image is black and white. | Image is colored. |
Resolving power is 0.5 -5.0 A0, through theoretically it can be 0.25 A0. | Resolving power is 0.25µm or 250nm (2500A0). |
Magnification is up to 300,000. | Magnification is upto 4000. |
Electron microscope is used in the study of external surface(Scanning Electron Microscope SEM) , ultra structure of cell and very small organisms(Transmission Electron Microscope TEM). | It is used for the study of detailed gross internal structure. |