Difference between Light Microscope and Electron Microscope (Light Microscope vs Electron Microscope)

Light microscope has useful magnification of 500x to 1500x. The source of illumination for object is the visible wavelength ranging from 3900 A⁰ to 7600 A^0.   Smaller organelles like lysosomes, ribosomes (smaller than 0.20μ) cannot  be seen under this light microscope. Another draw back of this microscope is that living cells cannot be observed directly. They are to be first killed, fixed and stained which may alter the shape and contents of cell. 

Microscopic Techniques

Electron microscope (EM) is an instrument which permits a direct study of biological ultra structure. Electron microscope was discovered by M.Knoll and E. Ruska of Germany (1932).  Its resolving power is about 250 times than that of the light microscope. The essential constituents assembled vertically are as  a) an illuminating system b) a specimen chamber c) an objective lens, d) intermediate and projecting lens and e) a viewing chamber with facilities for photographing electron images. 

Difference between:  Light Microscope vs Electron Microscope

	Light Microscope	Electron Microscope (EM)
1	Techniques are simple	High level of technical skill needed
2	Specimen preparation normally takes a few minutes to few hours	Specimen preparation often takes several days
3	Live or dead specimens may be seen	Only dead and dried specimens can be seen
4	Surface view  of the specimen is poor	Good surface details (SEM) or internal details (TEM) can be seen.  (refer:SEM vs TEM)
5	Light rays are used to illuminate the specimen.	Electron beam produced by the cathode is used
6	Condenser, objective and eye piece lenses are made of glass.	All lenses are electromagnets.
7	Resolving power
	Light microscope has low resolving power i.e., below 0.25 μm to 0.30 μm.	Electron microscope ha high resolving power i.e., about 250 times more than light microscope. Thus it can resolve down to 0.0001 μm.
8	Magnification
	It has a useful magnification of 500x to 1500x.	EM has direct magnification as high as 160,000x and photographic magnification is 1000,000x or more
9	Mechanism of image formation
	In light microscope the image formation depends upon of light absorption in different zones of the objects.	In electron microscope, it is due to electron scattering.
10	Image is seen by eyes through ocular lens. No screen is needed.	The image is received on zinc sulphate fluorescent screen or photographic plate.(SEM vs TEM)
11	No vacuum is needed	EM operates at high vacuum
12	Cheap and negligible running cost	Very costly and heavy running costs