Introduction to use of microscopes

Question 1

Clinical relevance of microscopes

Answer 1

• Distinguish normal tissue from abnormal tissue (BIOPSY)

- Identify source of abnormal tissue

Question 2

How to denature proteins to prepare for a specimen

Answer 2

• heat
• freezing
• chemicals; Formaldehyde, gluteraldehyde, alcohol

Question 3

What are the most common stains to stain a specimen

Answer 3

H&E

haematoxylin and eosin

Question 4

what is haematoxylin and whats it used to stain

Answer 4

basic dye
stains acid components a purple/blue
basophilic e.g. nuclei

Question 5

what’s eosin and whats it used to stain

Answer 5

acidic dye
stains basic components pink
acidophilic e.g. cytoplasm

Question 6

What’s used to stain sugars and what does it do

Answer 6

PAS- oxidises sugars and stains resulting aldehydes a bright pink/purple

Question 7

What cells can be seen with the naked eye

Answer 7

ovum

Question 8

what can be seen with a light microscope

Answer 8

Most cells e.g. red blood cells

Question 9

What organelles can be seen with a light microscope

Answer 9

Nuclei

Mitochondria

Question 10

What can only be seen with an electron microscope

Answer 10

Ribosomes

Question 11

What’s the path of light in a simple condenser

Answer 11

Light source
Condenser
Stage
Objective and eyepiece
Eye

Question 12

How to set up a microscope above the stage

Answer 12

• set lamp brightness
• place slide on stage
• focus specimen at low power using coarse and then fine focus
• adjust individual eyepieces and interocular distance

Question 13

how to set up a microscope below the stage

Answer 13

• Close the field diagram
• Focus image using a condenser focus
• Centre the illumination
• Adjust the condenser diaphragm so just brightest

Question 14

What are the names of the main histological stains

Answer 14

H&E
PAS
Elastin
Trichrome