Histology Quiz 4

What type of tissue is the routine program on the tissue processor used for

Most tissue types

How long does the routine program on the tissue processor typically take

12-14 hours

What kind of sample is the biopsy program for on the tissue processor

Small tissues

What kind of sample is the extended program on the tissue processor used for

Dense or fatty tissues

what does dehydration do

removes free water from the tissues

Dehydrating agents are either

Hydrophilic reagents or dehydrating reagents

How do hydrophilic reagents work

By attracting water from the tissue

How do dehydrating reagents work

aqueous tissue fluids are diluted

What are the 2 types of dehydrating agents

Alcohols and acetone

What is the best dehydrating agent

Ethanol

How do you dispose of ethanol

recycle it

what dehydrating agent has a primary use of fixing blood smears

Methanol

what dehydrating agent can cause blindness or death

Methanol

what is the best substitute for ethanol

isopropanol

what dehydrating agent does not cause as much tissue shrinkage as ethanol

Isopropanol

how to dispose of isopropanol

recycle

what dehydrating agent is not absolute and contains 1% water

isopropanol

what dehydrating agent is used for the dehydration of plant and animal materials

Butanol

What dehydrating agent causes rapid dehydration and is inexpensive

Acetone

what dehydrating agent easily evaporates and absorbs water when exposed to air

Acetone

What is the flashpoint of Acetone

-17 degrees C

what dehydrating agent has a flashpoint of -17 degrees C

Acetone

what can happen if the tissue has insufficient dehydration

Tissue is soft and mushy

what can happen if the tissue has excessive dehydration

tissue is overhardened and brittle

what is a universal solvent

reagents that have dehydrating and clearing functions

what are the effects on tissue when using a universal solvent

significant distortion to tissues

what are universal solvents rarely used

they are highly toxic

what is dioxane an example of

universal solvent

what is tertiary butanol an example of

universal solvent

what is tetrahydrofuran an example of

universal solvent

xylene is what type of agent

a clearing agent

what is an aromatic hydrocarbon

agents that make tissues clear

what is limonene a substitute for

xylene

what clearing agent has a citrus odor and is less hardening than xylene

limonene

what is aliphatic hydrocarbon a substitute for

xylene

what clearing agent is lightweight, water intolerant and possibly not compatible with the mounting media for coverslips

aliphatic hydrocarbons

what clearing agent is used at NSCC

aliphatic hydrocarbons

what is the most used clearing agent

xylene

prolonged exposure to xylene causes tissues to

overharden

what happens if xylene mixes with water

it goes cloudy

what clearing agent is a neurotoxin and causes CNS damage

xylene

how do you dispose of xylene

via controlled methods

what type of clearing agent is toluene

aromatic hydrocarbon

what clearing agent is more volatile than xylene

toluene

what type of clearing agent is benzene

aromatic hydrocarbon

what clearing agent will not overharden tissues like xylene

benzene

what clearing agent is a carcinogen to blood and bone marrow

benzene

what clearing agent just should not be used because of how dangerous it is

benzene

chloroform is what kind of agent

clearing agent

what clearing agent makes tissues less brittle than xylene

chloroform

what are the downsides to chloroform

slowly clears tissues and is difficult to dispose of

what happens if tissues are insufficiently cleared

tissues will be soft and mushy

what happens if tissues are excessively cleared

excessive tissue hardening

what happens to tissues if there is water contamination during the clearing stage

slides stain unevenly

what is the purpose of infiltration

to give rigidity and structure to tissue for cutting

what is the most popular embedding media

paraffin

what is the melting point of paraffin

55-58 degrees C

paraffin is a combination of

beeswax, rubber and plastics

paraffin with a higher melting point…

gives better tissue support, allows for thinner sections to be cut but makes ribboning difficult

paraffin with a lower melting point,,,

gives less tissue support, is harder to cut in thin sections but makes ribboning easier

what is the only reagent to apply heat during the infiltration stage

paraffin

what type of embedding media is only used for special projects

water soluble wax

what embedding media does not require the use of dehydrating or clearing agents

water soluble wax

what embedding media is used with friable tissue/ multiple fragments of tissue

Agar and gelatin

what embedding media combines all pieces into a block, a process known as ‘double embedding’

agar and gelatin

what type embedding media provides excellent support for decalcified bone

glycol methacrylate

how are sections embedded using glycol methacrylate cut

using a glass knife

what types of tissue is glycol methacrylate good for

kidney, lymph node biopsies and bone marrow

when is epoxy resin used as an embedding media

for electron microscopy

how are tissues embedded in epoxy resin cut

with a diamond knife

what is the order for reverse processing

paraffin, xylene, 100% ethanol

what does reverse processing do

completes dehydration