1.1 Microscopy

Question 0

What are two differences between TEM and SEM?

Answer 0

TEM: 2D image
SEM: 3D image
TEM: electrons pass through specimen
SEM: electrons do not pass through specimen

Question 1

Magnification and Resolution

Answer 1

Light Microscope: x1500 200nm
Transmission EM: x500 000 0.1nm
Scanning EM: x100 000 0.1nm

Question 2

Give three advantages of using electron microscope?

Answer 2

(1) Much high resolution
(2) 3D image can be produced
(3) More detail

Question 3

Give three disadvantages of using an electron microscope?

Answer 3

(1) Expensive
(2) Requires skill to prepare sample
(3) Vacuum condition; boils water

Question 4

What does staining do to a sample?

Answer 4

Increases contrast
Chemicals bind into specimen
Makes sections of specimen more visible

Question 5

What is sectioning?

Answer 5

When specimens are embedded in wax, so thin sections can be cut out without distorting the specimen