Light Microscopy (Labster Lab Manual | P)

Question 1

What is light microscopy?

Answer 1

1) It is the most commonly used microscopy technique

2) It often requires staining of the sx to be able to visualize the structures of interest

Question 2

What is the minimal resolution of a light microscope?

Answer 2

Approximately 200 nm

Question 3

What is minimal resolution?

Answer 3

It is defined as the distance between 2 points that are still distinguishable as 2 separate entities

Question 4

What are the components that limits resolution?

Answer 4

1) Physical properties of light

2) Lens of the microscope

Question 5

Explain the relationship between wavelength of light and resolution

Answer 5

The shorter the wavelength: the better the resolution

Question 6

Does the wavelength of light limits resolution?

Answer 6

Yes

Question 7

Does the aperture value of the objective lens limit the resolution?

Answer 7

Yes

Question 8

Where is immersion oil placed?

Answer 8

A drop of immersion oil is place between the cover slip of the slide and the objective lens

Question 9

What happens if there is absence of immersion oil?

Answer 9

The light is refracted when it moves from glass to air and back into the glass of the objective lens

Question 10

What happens if immersion oil is applied?

Answer 10

If immersion oil having the same optical identity as glass is done, the effect of refraction is diminished and the minimal resolution can be achieved

Question 11

Can some sxs be simply mounted on a slide?

Answer 11

Yes

Question 12

Is light microscopy ideal to visualize process in living cells?

Answer 12

No

Question 13

What is the general process for histology preparations?

Answer 13

1) Fixation
2) Dehydration
3) Embedding
4) Sectioning
5) Mounting
6) Staining

Question 14

What is the function of chemical fixatives?

Answer 14

To preserve tissue by preventing degradation and help to maintain the structure of the cell and of sub-cellular components

Question 15

What is the most common fixative for light microscopy?

Answer 15

10% neutral buffered formalin

Question 16

What is dehydration?

Answer 16

Water is removed from the sx as it does not mix with embedding media

Question 17

What is embedding?

Answer 17

The sx is embedded in a solid external matrix to facilitate sectioning

Question 18

What is sectioning?

Answer 18

The sx is cut into thin sections

Question 19

The thickness of sections as a result of sectioning depends on what?

Answer 19

It depends on the sx and research question

Question 20

What is the thickness of the slices for routine histology?

Answer 20

2-5 mm thick

Question 21

What is mounting?

Answer 21

Attaching sxs to the microscope slide

Question 22

What is staining?

Answer 22

Sx is stained to add contrast and label structures of interest