Microscopes

Question 1

What is a light microscope and how does it work?

Answer 1

It uses lenses to focus a beam of light through a specimen
Lower resolution
Can view live specimens in colour
Simple preparation

Question 2

What is an electron microscope and TEM and SEM

Answer 2

It uses electromagnets to focus a beam of electrons through or onto a specimen
Denser parts absorb more electrons and appear darker
Has higher resolution than light due to smaller wavelength of electrons
Specimen must be placed in a vacuum so must be dead
Has long preparation time with complex staining procedure which can produce artefacts

TEM
Can see internal structure as electrons transmit
Extremely thin
Image in 2D
Black and white image only
SEM
Resolution not as high as TEM
3D image as only surface is scanned
Black and white image only

Question 3

How do you make a mount?

Answer 3

add a drop of water
Add a single layer of cells
Add a drop of stain
Add coverslip and push down gently