IMPREGNATION/INFILTRATION

Question 1

Process whereby the clearing agent is completely removed from the tissue and replaced by a medium that will completely fill all the tissue cavities, thereby giving a firm consistency to the specimen, and allowing easier handling and cutting of suitably thin sections without any damage or distortion to the tissue and its cellular components

Answer 1

IMPREGNATION

Question 2

SIMPLEST, MOST COMMON AND BEST EMBEDDING MEDIUM

Answer 2

Paraffin wax

Question 3

Tissue:Infiltrating medium ratio

Answer 3

1:25

Question 4

Melting point of Paraffin wax

Answer 4

55-60°C

Question 5

3 ways by which paraffin wax impregnation and embedding of tissues may be performed

Answer 5

Manual Processing
Automatic Processing
Vacuum Embedding

Question 6

Paraffin wax requires at least ____ changes of melted wax at ____ intervals to ensure complete removal of clearing agent from the tissue; tissue is immersed in another solution of melted wax for approximately ____ to ensure complete embedding of tissue

Answer 6

4
15 minutes
3 hours

Question 7

Automatic tissue processing machine

Answer 7

Autotechnicon

Question 8

Processes done by the automatic tissue processor

Answer 8

Fixation
Dehydration
Clearing
Infiltration

Question 9

Involves wax impregnation under negative atmospheric pressure inside an embedding oven to hasten removal of air bubbles and clearing agent from the tissue block, promoting a more rapid wax penetration of tissue

Answer 9

Vacuum Embedding

Question 10

Recommended for urgent biopsies, for dense and hard fibrous tissues, for lungs, spleen, and other delicate tissues

Answer 10

Vacuum Embedding

Question 11

Total impregnation time depends on:

Answer 11

Nature and size of the tissue
Type of clearing agent used

Question 12

Substitutes for Paraffin Wax

Answer 12

Paraplast
Ester wax
Water soluble waxes

Question 13

Mixture of highly purified paraffin and synthetic plastic polymers

Answer 13

Paraplast

Question 14

Melting point of Paraplast

Answer 14

56-57°C

Question 15

Has a lower melting point (46-48°C) but is harder than paraffin

Answer 15

Ester wax

Question 16

Mostly polyethylene glycols with melting points of 38-42°C or 45-56°C

Answer 16

Water soluble waxes

Question 17

Most commonly used Water soluble waxes

Answer 17

Carbowax

Question 18

Purified form of nitrocellulose. Specimens with large hollow-cavities which tends to collapse (e.g., eyes), for hard and dense tissues (e.g., bones, teeth), and for large tissue sections of the whole embryo

Answer 18

Celloidin (Collodion)

Question 19

2 methods of Celloidin impregnation

Answer 19

Wet celloidin method
Dry celloidin method

Question 20

Recommended for bones, teeth, large brain sections, and whole organs

Answer 20

Wet celloidin method

Question 21

Referred for processing of whole eye sections

Answer 21

Dry celloidin method

Question 22

Rarely used except when dehydration is to be avoided and when tissues are to be subjected to histochemical and enzyme studies

Answer 22

GELATIN IMPREGNATION

Question 23

Eyes

Answer 23

Bioloid