Tissue Processing (Wk 3)

Question 1

Unlike xylene, this clearing agent doesn’t make tissues transparent

Answer 1

Chloroform

Question 2

A paraffin processed block of liver which is mushy and soft is likely caused by:

A ) water in the absolute ethanols.

B ) Too much time in wax.

C ) The use of xylene as a clearing agent.

D ) Any of the above.

Answer 2

A ) water in the absolute ethanols.

Question 3

CHCl3 is:

A ) Carbon tetrachloride
B ) Thionyl chloride
C ) Chloroform.
D ) Acetone.

Answer 3

C ) Chloroform.

Question 4

Usual melting point of wax

Answer 4

56-58 degC

Question 5

Purpose of eosin or phloxine as additives to alcohol

Answer 5

Help visualize small pieces of tissue (both dyes)

Question 6

Micro chatter may be caused by this problem during tissue processing

Answer 6

Over dehydration

Question 7

Cause of soft, mushy blocks

Answer 7

Under dehydration

Question 8

Why is ethanol preferred over isopropanol for processing

Answer 8

Isopropanol is larger compared to ethanol = doesn’t penetrate as effectively = dried out on outside and unprocessed in the center

Question 9

Which step of processing is non-reversible

Answer 9

Fixation

Question 10

Purpose of phenol or Molliflex as additives to alcohol

Answer 10

Help soften hard tissue

Question 11

The usual temperature that wax baths are maintained at is?
 A )   37
 B )   52
 C )   60
 D )   67

Answer 11

C ) 60

Question 12

Anhydrous copper sulphate is sometimes added to which of the following?

A ) Chloroform
B ) Xylene
C ) Ethanol
D ) Wax

Answer 12

C ) Ethanol

Question 13

A clearing agent for use in processing tissues for paraffin embedding must be miscible with the?

A ) fixative and paraffin
B ) dehydrant and paraffin
C ) fixative and dehydrant
D ) paraffin and water

Answer 13

B ) dehydrant and paraffin

Question 14

Consequence of removing BOUND water?

Answer 14

Tissue is overly hard, difficult to cut

Question 15

This chemical may be added to ethanol to make it un-drinkable

Answer 15

Benzene

Question 16

The major objection for the use of xylene as a clearing agent for processing tissues is that xylene is?

A ) likely to harden tissue
B ) hygroscopic
C ) only slightly miscible with wax
D ) the most volatile of hydrocarbons

Answer 16

A ) likely to harden tissue

Question 17

Poor nuclear detail is the symptom of which one of the following?

A ) Too long a time in chloroform

B ) Not enough time in ethanol

C ) Over exposure to paraffin wax

D ) Too long in Nitric acid

Answer 17

D ) Too long in Nitric acid

Question 18

What process involves the introduction of a wax solvent into the tissue?

A ) fixation
B ) dehydration
C ) clearing
D ) impregnation

Answer 18

C ) clearing