What kind of microscope is to be used to see smaller organelles, and how do these work?

A light microscope is sufficient to see the shape of the
cell and its nucleus.  However, to see the smaller organelles, you would want to use an
electron microscope.

Electrons are fired into a vacuum
sealed container.  A positively charged electrode accelerates the electrons into a
beam.  The electron beam passes through an electromagnetic coil, which focuses the beam
on the specimen.  The electrons bounce off the specimen and into a detector, which then
interprets the data into a magnified
image.

Source:

title="Electron microscopes. Chris Woodford. Explain That Stuff!"
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