Adv. Techniques in Microscopy

Question 1

Give 5 examples of light microscopy

Answer 1

Bright-field, Phase Contrast, Differential Interference Contrast, Fluorescence, Confocal Laser/Fluorescence

Question 2

Give the 2 types of electron microscopes

Answer 2

Transmission and Scanning

Question 3

What are light microscopes good for examining?

Answer 3

Tissue specimens

Question 4

What are the advantages of digital microscopes?

Answer 4

Very high resolution, use a low heat light source so good for examining living cells

Question 5

When is phase contrast microscopy used?

Answer 5

Used when specimens appear transparent when bright-field illumination is used. Can be used to examine dynamic events in living cells

Question 6

Who invented differential interference contrast microscopy?

Answer 6

Nomarski

Question 7

Give 2 examples of fluorescent dyes

Answer 7

Fluorescein (green emission), Rhodamine (red emission)

Question 8

Explain immunofluorescence microscopy

Answer 8

Uses antibodies linked to a fluorescent dye to detect specific proteins in a cell

Question 9

What is a ‘vital’ fluorescent dye used for? Give an example

Answer 9

For staining (parts of) living cells. FM 4-64, a hydrophobic dye that only stains membranes`

Question 10

What is a GFP?

Answer 10

A Green Fluorescent Protein is a protein that fluoresces under UV light excitation

Question 11

What is FRET?

Answer 11

Förster/Fluorescence Resonance Energy Transfer. Based on GFP technology.

Question 12

What is Confocal Laser/Fluorescence used for?

Answer 12

Used for examining a transection through the sample

Question 13

What is the resolution of TEM?

Answer 13

Can be as low as 0.1nm

Question 14

For TEM, what kind of material is used for staining the sample?

Answer 14

Electron dense materials eg gold, osmium

Question 15

What is immunoelectron microscopy?

Answer 15

Where gold particles are attached to antibodies to detect specific particles

Question 16

What is the resolution of SEM?

Answer 16

~10nm

Question 17

What is the resolution of SEM?

Answer 17

~10nm

Question 18

What is TEM used for?

Answer 18

Examining the fine structure of organelles

Question 19

What is SEM used for?

Answer 19

Examining the surface topography

Question 20

For SEM, what kind of material is used for staining the sample?

Answer 20

A heavy metal eg platinum

Question 21

What is ESEM?

Answer 21

Environmental SEM. A SEM that allows a gaseous environment in the specimen chamber, meaning live specimens can be examined. All other electron microscopes operate in a vacuum.