EMBEDDING AND INFILTRATION Flashcards
trans base
Process that removes the clearing agent
impregnation
3 types of general tissue impregnation
paraffin wax impregnation
celloidin impregnation
gelatin impregnation
range temp of actual melting wax
56 celcius
58 celsius
solid in form upon procurement thus we need to melt it first in order for us to have it in
liquid form.
paraffin wax
must be maintained 2-5°C above
the melting point of wax
paraffin oven
what coarse filter must be used in impregnation
Green’s No. 904
3 Ways of Paraffin Wax Impregnation
manual processing
automatic processing
vacuum embedding
how many changes of paraffin dp we do in manual processinh and how long per beaker/change
3 changes of paraffin, 1hr per beaker/change
how many stations are there in automatic processing and infiltration will take up at what stations?
12 station; 11 and 12
fastest way of embedding yet the most expensive
vacuum embedding
more elastic and resilient
Paraplast
Less brittle, and less compressible
Embeddol
semisynthetic; for embedding of eyes
Bioloid
melting point of paraplast
56-57°C
melting point of embeddol
56-57°C
melting point of ester wax
46-48°C
melting point of water soluble waxes (polyethylene glycol)
38-42 or 45-56 celsius
most common water soluble wac and no need for dehydration and clearing
Carbowax
remedy for carbowax
add soap to water or 10% PEG 900 in water
Purified form of nitrocellulose/gun cotton
colloidin
concentrations in celloidin impregnation
2%
4%
8%
- for bones, brain, teeth
◆ Store tissue block in 70%-80% alcohol
◆ The purpose of storing it in this
concentration is to avoid dehydration and
shrinkage of the tissue.
wet
- for whole eye sections
◆ Store tissue block in Gilson’s Mixture
(chloroform and cedarwood oil)
dry
Has lower viscosity, thus can be used in higher concentration, and rapid tissue penetration
Nitrocellulose
Needed to prevent tissue cracking in chrome mordanted tissues
Plasticizer
rarely used impregnation
gelatin impregnation
must be added to prevent molds and prevent further damage such as tissue decay
1% phenol
Placing the impregnated tissue into a mold with embedding media, and then allowing the media to solidify
embedding
other terms for embedding
casting
blocking
molding
orientation for tubular tissue
transverse sections
orientation for skin
all layers should come
orientation for endomatrial curetting
keep in center
orientation for long tissue
keep diagonally
orientation for intestine
all layers should come
orientation for membrane
swiss roll
types of molds
Leuckhart’s Embedding Mold
Compound Embedding Unit
Plastic Embedding Rings and Base Mold
Disposable Embeding Molds
It has two (2) L-shaped metal plates, strips of heavy brass metal.
Leuckhart’s Embedding Mold
This used for batch embedding thus one of its disadvantages is being prone to the interchanging of samples.
Compound Embedding Unit
This is for the ease of separation of the tissue block from the mold after it solidifies.
Disposable Embeding Molds
Tissues are first infiltrated with Celloidin and subsequently embedded in a paraffin mass; For large blocks of dense tissues; obsolete
double-embedding method
For high resolution light microscopy of thinner than
usual sections, renal biopsies, BM biopsies
plastic resin embedding
Most widely applied, but carcinogenic due to vinylcyclohexane dioxide (VCD)
component
epoxy
types of epoxy
● Bisphenol A (Araldite) - slow
● Glycerol (Epon) - low viscosity
● Cyclohexene dioxide (Spurr) -
very low viscosity; fastest
For electron microscopy; seldom used
polyster
For high resolution light microscopy
acrylic plastics
catalyst; forms radicals which are site for polymerization
benzoyl peroxide
