Infiltration / Impregnation

Question 1

Three Infiltration Method

Answer 1

1. Paraffin Wax Infiltration Method
2. Celloidin Infiltration Method
3. Gelatin Infiltration Method

Question 2

infiltration method not suited for fatty tissues

Answer 2

Paraffin Wax Infiltration Method

Question 3

melting point of paraffin wax commonly used

Answer 3

56° Celsius

Question 4

temperature range of paraffin oven when in used

Answer 4

55 - 60° Celsius

Question 5

higher than the wax melting point : approximate temperature of paraffin oven when in used

Answer 5

2-5 ° Celsius

Question 6

Methods of Paraffin Wax Impregnation

Answer 6

• Manual (4 changes of wax)
• Automatic (2-3 changes of wax)
• Vacuum Infiltration

Question 7

facilitates removal of transition solvents & prolongs life of wax by reducing solvent contamination

Answer 7

Vacuum Infiltration

Question 8

• negative atmospheric pressure inside oven
• processing time is reduced because the tissue is subjected to very high temperatures

Answer 8

Vacuum Infiltration

Question 9

Substitute of Paraffin Wax

Answer 9

PARAPLAST
CARBOWAX
BIOLOID
ESTER WAX

Question 10

substitute for paraffin wax recommended for bones and brain specimens

Answer 10

paraplast

Question 11

paraplast melting point

Answer 11

56-58 ° Celsius

Question 12

ester wax melting point

Answer 12

48 ° Celsius

Question 13

substitute for paraffin wax that will require heavy duty type of microtome

Answer 13

ester wax

Question 14

substitute for paraffin wax used for eye specimens

Answer 14

bioloid

Question 15

○ Polyethylene glycol containing 18 or more carbon atoms
○ appears solid at room temperature

Answer 15

carbowax

Question 16

○ substitute for paraffin wax that is water soluble & is recommended for enzyme histochemical studies

Answer 16

carbowax

Question 17

• infiltration method recommended for specimens with large and hollow cavities that tends to collapse

Answer 17

celloidin infiltration method

Question 18

combination of chloroform & cedarwood oil

Answer 18

Gilson’s mixture

Question 19

● recommended for whole eye specimen
● will require use of Gilson’s mixture to store
blocks

Answer 19

dry celloidin

Question 20

• recommended for bone, teeth, large brain sections, whole organs & teeth specimen
• will require 70-80% alcohol to store blocks

Answer 20

wet celloidin

Question 21

dry celloidin will require _ to store blocks

wet celloidin will require _ to store blocks

Answer 21

dry: Gilson’s mixture
wet: 70-80% alcohol

Question 22

much preferred than the ordinary celloidin for both infiltration & embedding

Answer 22

Low Viscosity Nitrocellulose

Question 23

soluble in ether and alcohol
● lower viscosity → can use in high concentration & still penetrate tissue rapidly

Answer 23

Low Viscosity Nitrocellulose

Question 24

Low Viscosity Nitrocellulose
— disadvantage: tendency to crack
prevention:

Answer 24

prevention: adding plasticizers like Oleum ricini or castor oil

Question 25

infiltration method recommended for enzyme and histochemical studies

Answer 25

gelatin infiltration method

Question 26

• recommended only if dehydration is avoided
• infiltration method that will require tissues not to be more than 2 -3mm thick

Answer 26

Gelatin Infiltration Method

Question 27

Use of phenol in gelatin infiltration:

Answer 27

to prevent molds