2. Microscopy

Question 1

Key components of optical microscope

Answer 1

Eyepiece lens, objective lenses, stage, light source, coarse and fine focus

Question 2

Tools used when preparing specimen

Answer 2

Forceps
Scissors
Scalpel
Coverslip
Slides
Pipette
Staining solution

Question 3

How to prepare slide for liquid specimen

Answer 3

• add few drops of sample to slide using pipette
• cover liquid with coverslip and gently press down to remove air bubbles
• wear gloves to ensure no cross contamination of foreign cells

Question 4

How to prepare slide for solid specimen

Answer 4

• use scissors to cut small sample of tissue
• peel away or cut very thin layer of cells from the tissue sample to place on the slide using forceps
• tissue needs to be thin so light from microscope can pass through
• apply a stain
• place coverslip on top and press down to remove any air bubbles

Question 5

What does eosin stain & what colour

Answer 5

Cytoplasm, collagen, connective tissue. Orange/red

Question 6

What does Nile blue stain

Answer 6

Nuclei blue

Question 7

What does Sudan red stain

Answer 7

Lipids/ triglycerides (cell membrane) red

Question 8

What does iodine stain

Answer 8

Starch blue/ black

Question 9

Different types of microscope

Answer 9

Light
Transmission electron
Scanning electron
Laser scanning confocal

Question 10

Resolution definition

Answer 10

Minimum distance apart that 2 objects can be distinguished as separate objects in an image

Question 11

What’s the smallest resolution a light microscope can resolve to

Answer 11

0.2μm

Question 12

What’s the smallest resolution transmission electron microscopes can resolve to

Answer 12

0.1nm-0.2nm

Question 13

What’s the smallest resolution a scanning electron microscope can resolve to

Answer 13

1-10nm

Question 14

Which microscope can be used to view live specimens

Answer 14

Light

Question 15

What are approximate costs of the different microscopes

Answer 15

Light: £500
TEM: £1m +
SEM: £500k-£1m