Slide Preparation

Question 1

Order of slide prep

Answer 1

1. Dissection
2. Fixation
3. Dehydration
4. Clearing
5. Embedding
6. Sectioning
7. Staining
8. Resolution

Question 2

Dissection

Answer 2

Removing a small piece of tissue

Question 3

Paraffin dissection

Answer 3

5 mm thick and 1-2 cm long

Question 4

Epoxy Dissection

Answer 4

1 mm thick

Question 5

Paraffin is used for which microscope?

Answer 5

Light microscope (mostly)

Question 6

Epoxy is used for what microscope?

Answer 6

Electron transmission microscope (mostly)

Light microscope

Question 7

Fixation

Answer 7

Tissue preservation
Harden tissues and prevents autolysis
2 types: immersion and intravascular fixation

Question 8

Immersion fixation

Answer 8

Immersing tissues in a jar roughly 20 times the volume of the tissue

Question 9

Intravascular Perfusion

Answer 9

Fixative injection via blood vessels

Question 10

Why shouldn’t you use a water based fixative for glycogen?

Answer 10

Because it’s soluble in water and can eliminate

Question 11

Paraffin fixation

Answer 11

Formaldehyde (4%)

formalin, alcohol and freezing

Question 12

Epoxy fixation

Answer 12

Glutaraldehyde (2%)
Osmisum Tetroxide (1%)

Question 13

Dehydration

Answer 13

Removing water by immersing tissues in graded concentration of alcohol or acetone
50–>60–>70–>80–>90–>100%
Same used for both epoxy and paraffin

Question 14

Clearing

Answer 14

To make tissues transparent so epoxy or paraffin is easily infiltrated

Question 15

What is used for both paraffin and epoxy clearing?

Answer 15

xylenen, benezene and chloroform

Question 16

Embedding

Answer 16

Cleared tissues embedded with epoxy (LM or EM) or paraffin (LM)

Question 17

Sectioning

Answer 17

Cut sections thin enough so light or electrons can penetrate

Question 18

How thick should sectioning be for paraffin?

Answer 18

5-7 micrometers thick

Question 19

How thick should sectioning be for epoxy?

Answer 19

1 micrometer for LM

50-80 nm for EM

Question 20

Staining for paraffin

Answer 20

H&E staining because it adds color for contrast

Question 21

Staining for Epoxy

Answer 21

Heavy metal staining (lead citrate and uranyl acetate) because it increases electron density and contrast

Question 22

Resolution for paraffin

Answer 22

0.5 micrometers

Question 23

Resolution for Epoxy

Answer 23

0.5 nm