Electron microscopy.

https://www.youtube.com/watch?v=Q9AEphhdXMA

How do electron microscopes work

Use electrons instead of light, they have very short wavelengths, so resolution is 2000 x better than light microscope.

How does electron microscope work

Starts with electron gun producing beam of electrons, they pass down microscope which contain a vacuum inside, so electrons pass throug hwithout bouncing of molecules in air.

Specimen is placed in microscope, image is produced on fluorescent screen.

Electron microscopes advantages

Electron microscopes have a 2000x better resolution than light microscopes.

Electron microscope disadvantages

Interior of an electron microscope is vacuum, we cannot view living specimens

Electron microscopy requires very careful staining, specimen has to be very thin

Electron microscopy can lead to artefacts (false images)

What is transmission electron microscope

Electron beam passes through specimen, produces 2d images, only works if specimen thinly sliced. It does have very high resolution

Whats scanning electron microscope.

The electron beam does not pass through the specimen, electrons are instead scattered from the surface of the specimen , and detected

Produces 3d images, does not require specimen to be thinly sliced,

It has a lower resolution than transmission electron microscope

Also requires specimen is coated with a metal such as gold, can lead to artefacts.