Clearing

Flashcards based on lecture notes covering dehydration, clearing, and decalcification techniques in histopathology and cytology.

What is another name for Ethylene Glycol Monoethyl Ether?

Cellosolve

At what temperature does Ethylene Glycol Monoethyl Ether become combustible?

110-120°F

What systems can Ethylene Glycol Monoethyl Ether be toxic to upon prolonged exposure?

Reproductive, fetal, urinary, and blood systems

What environmental factor causes Ethylene Glycol Monoethyl Ether to decompose?

Sunlight

For what types of specimens is Triethyl Phosphate used?

Sections and smears

What is a major advantage of using Triethyl Phosphate for dehydration?

Causes only minimum shrinkage

What are other names for Tetrahydrofuran?

THF

What two processes can Tetrahydrofuran perform on tissues at the same time?

Dehydrate and clear

What are some symptoms of inhaling Tetrahydrofuran vapors?

Nausea, dizziness, and headache

What type of irritation can Tetrahydrofuran cause?

Conjunctival irritation

What is the general purpose of dealcoholization or clearing?

Removal of dehydrating agent from tissues and replace it with a medium that will dissolve the wax.

What property does clearing impart to tissues?

Transparency

What index does clearing improve?

Refractive index

What staining issues can arise from incomplete clearing?

Uneven H and E staining and poor nuclear chromatin patterns

What happens to tissues with prolonged clearing time?

Tissues become brittle

What is a common routine clearing agent?

Xylene

How fast does Xylene typically act as a clearing agent?

Fast acting

For what tissue types is Xylene NOT suited?

Nervous tissues and lymph nodes

What happens to Xylene when an incompletely dehydrated tissue is immersed in it?

It becomes milky

What are the substitutes for xylene and benzene?

Toluene

What happens to Toluene in a partially filled vessel?

Acidifies

For what type of biopsies is Benzene suited?

Urgent biopsies

What is a potential danger from prolonged exposure to Benzene?

Damage to the bone marrow leading to aplastic anemia

What clearing agent is especially flammable and carcinogenic?

Benzene

Is Chloroform a routine clearing agent?

No

For what types of tissues is Chloroform used?

Rough tissues (skin, fibroid, and decalcified tissues), nervous tissues, lymph nodes, and embryos

What can be done to prevent tissues from floating in Chloroform?

Wrap tissue in a gauze

What organ is Chloroform toxic to?

Liver

What visual characteristic do tissues NOT display after being cleared with Chloroform?

Translucence

How does Chloroform affect wax?

Can lead to wax deterioration

How long is the typical clearing time for Cedarwood oil?

2-3 days

For what types of studies is Cedarwood oil useful?

Cytological studies like smooth muscles of skin and for CNS tissue

What types of specimens is Aniline Oil used for clearing?

Embryos, insects, and other very delicate specimens

What happens to tissues cleared with Clove Oil?

Tissues tend to become adulterated

What clearing agent is similar to Chloroform but cheaper?

Carbon tetrachloride

When are Methyl benzoate, amyl acetate, and methyl salicylate used?

Only in double embedding process

What is N-butyl acetate used as?

Xylene substitute

From what source is Limonene obtained?

A citrus fruit

What type of tissue does Oil of Bergamot clear?

Smooth muscles of the skin

What type of tissue does Oil of Origanum clear?

Smooth muscles of the skin

What type of tissues does Oil of Wintergreen clear?

Delicate tissues

What type of tissues does Carbon disulfide clear?

Smooth muscles

What is a distinct characteristic of Carbon disulfide?

Foul odor

What type of tissues does Carbon xylene clear?

Friable tissues

For what type of specimen is Terpineol suited?

Eyes

What characteristic of Terpineol makes it a good substitute for Cedarwood oil?

Low evaporation rate

What is High Test Aviation Lead Free gasoline an excellent clearing agent for?

Not specified in text.

What hazardous effect makes benzene not the most optimal clearing agent?

Highly flammable and carcinogenic

Which clearing agent is best suited for delicate skin tissues?

Oil of bergamot

What is the main purpose of using clearing agents?

To make tissues transparent and improve their refractive index