microscopy

pros of optical microscope

can view live specimens, relatively cheap, easy to transport

cons of optical microscope

preservation and stains can produce artefacts, limited powers of magnification and resolution

pros of transmission electron microscopes (tems)

give high resolution images so shows small objects and internal structures

cons of transmission electron microscopes

can only be used on thin specimens, can only be used on dead specimens, require a vacuum, expensive

pros of scanning electron microscopes

can be used on thick specimens, can be 3d, high resolution and magnification

cons of scanning electron microscopes

lower resolution images than tems, can only be used on dead specimens, cannot see internal structures, requires a vacuum, expensive

how to transmission electron microscopes work

electron beam passes through thin section (<0.1 um) so internal structures can be seen, flat 2d image, requires a vacuum

how do scanning electron microscopes work

electron beam deflected off specimen so you can only see external structures, 3d images produced, resolving power 20nm, requires a vacuum