impreg nd embedding Flashcards
T/F: Cellosolve is used as an embedding medium.
False - Cellosolve is a dehydrating agent
T/F: Test tubes are one of the possible embedding molds.
T
T/F: After embedding, 10 ̊C temperature prevents cracking of the tissue block
T
hold and protect tissues during processing and help fit them on the chuck of the rotary microtome
tissue cassettes
T/F pencil should be used to label tissue cassettes because it is not washed off by formalin
T
last station in the tissue processor is the _________ stage, which allows paraffin to infiltrate the tissue.
wax infiltration
T/F agitation during the tissue processing helps to hasten fixation
T
typical time needed for paraffin to infiltrate the tissue during the embedding process
1 hr
another term for impregnation
infiltration
process of saturating the tissue with a medium to harden it and prevent distortion is called __________
impregnation / Infiltration
impregnation is the process of saturating the tissue with a medium, usually liquid ________.
paraffin
T/F the primary purpose of impregnation is to prevent degradation and harden the tissue for sectioning
T
before infiltration, tissue specimens should be immersed in ______
10% formalin
medium commonly used in both the infiltration and embedding processes
paraffin
Select: Impregnation
A) Tissue is hardened to preserve structure.
B) Liquid paraffin is used for infiltration.
C) Tissues are embedded in ice after impregnation.
D) Immersion in 10% formalin precedes infiltration.
A B D
another word for embedding
casting or blocking
process where the tissue is placed in a mold and solidified for sectioning
embedding
T/F paraffin used for embedding should be free from clearing agents and dust particles to ensure proper sectioning and must be rapidly heated to reduce wax crystal size
F - cooled
T/F forceps should be hot enough to prevent paraffin from solidifying when transferring tissue to the mold
t
purpose of immersing the mold into a shallow 10°C water bath after filling it with paraffin
hasten solidification of the paraffin
when cooling paraffin properly, the crystals should be _______ and _______ to each other.
small and contagious
in the embedding process, the tissue is placed in a mold filled with molten __________
paraffin wax
properly cooled paraffin should appear clear and homogeneous, without any layering
t
OOO: Embedding process
A) Fill the bottom of the mold with paraffin.
B) Submerge the tissue in 100% ethanol.
C) Use forceps to place the tissue into the mold.
D) Cool the mold in a 10°C water bath
B
T/F The paraffin should rapidly cool after embedding to reduce wax crystal size.
t
temperature used during the cooling of the paraffin to prevent cracking of the tissue block.
10°C
T/F The cold orientation platform or cold plate is used to freeze the paraffin block for solidification
T
paraffin block should be surrounded by at least _______ of paraffin on all sides
2 mm
embedding medium should be soluble in ___________ and should be easy to section and make ribbons
processing fluids
T/F the ideal embedding medium should be translucent, inert to the embedded material, and non-toxic
T
what temperature range should an ideal embedding medium be molten between?
30 to 60°C
T/F the properties of the embedding medium should not match those of the tissue being sectioned
F - should match
________ is the most common and simplest embedding medium used for routine tissue processing
paraffin
T/F paraffin becomes firm enough to section at room temperature after solidification.
T
Two key advantages of paraffin as an embedding medium
short infiltration time for small tissues
ability to form ribbons of sections
OOO: Substitute for paraffin wax
A) Paraplast
B) Fibrowax
C) Carbowax
D) Formalin
D - formalin is a fixative, not a paraffin substitute.
Select: Advantages of paraffin
A) Thin sections can be cut with a rotary microtome
B) Tissue can be stored indefinitely once embedded
C) Paraffin is difficult to solidify
D) Infiltration time for small tissue is short
A B D
paraffin substitute is a mixture of highly purified paraffin and synthetic plastic polymers
paraplast
T/F Bio/aid is recommended for embedding eyes
T
substitute of paraffin wax that is less brittle and less compressible than paraplast
embeddol
Ester Wax has a lower melting point of ___ and is harder than paraffin
46-48°C
ester wax is a substitute for paraffin waxes, which is a highly purified paraffin wax with ____, making it elastic & resilient
DMSO (dimethylsulfoxide)
T/F ester wax is soluble in water
F - not soluble in water; soluble in 95% ethyl alcohol and other clearing agents
Select: Characteristics of water-soluble waxes
A) Suitable for enzyme histochemical studies
B) Cytologic details are well preserved
C) Difficult to handle due to toxic nature
D) Has melting points between 38-42°C or 45-56°C
A B D
*A - carbowax
substitute for paraffin wax in which the histotechnologist may experience an unpleasant and annoying oyster or garlic taste
dimethyl sulphoxide (DMSO)
common disadvantage of using paraffin in tissue embedding
distortion of tissue histology due to shrinkage (paraffin artifact)
T/F Paraffin embedding can result in tissue distortion, especially when attaching sections to glass slides.
T
Select: Disadvantages of Paraffin
A) Distortion of the histology of the tissue due to shrinkage may occur, especially when sections are attached to glass slides (paraffin artifact).
B) Sectioning of paraffin is difficult at high temperatures.
C) The time for infiltration of large blocks of tissue is excessive.
A B C
Celloidin aka ______
colloidon
Celloidin is commonly used for ____ tissue specimens like bones and teeth, as well as ________ sections
hard tissue; large tissue
T/F celloidin requires heat during its embedding process
F - does not require
OOO: Advantage of Celloidin
A) Rubber-like consistency
B) Easy to prepare serial sections
C) Minimal specimen distortion
D) Does not require heat
B – difficult to prepare with Celloidin
Select: disadvantages of using Celloidin
A) Slow process
B) Difficult to cut thin sections
C) Tissue blocks must be stored in 100% alcohol
D) Blocks become discolored and dry in improper storage
a b d
wet celloidin is recommended for processing what types of specimens
Bones, teeth, large brain sections, and whole organs
T/F dry Celloidin is preferred for processing whole eye sections
T
what embedding medium is similar to Celloidin but has a lower viscosity, allowing rapid penetration of tissues
Low Viscosity Nitrocellulose (LVN)
Select: Advantages of Low Viscosity Nitrocellulose (LVN)
A) Low viscosity allows for higher concentration
B) Enables thicker sections
C) Greater speed of impregnation
D) Final block is harder, allowing thinner sections
A C D
OOO: Disadvantage of LVN
A) Tendency to crack during handling
B) Hard to cut thin sections
C) Highly explosive
D) Use of castor oil to prevent cracking
B - allows thin sections
what technique involves impregnating tissue with celloidin and then blocking it in paraffin wax
double embedding
T/F double embedding provides extra resilience for cutting hard tissues and allows for easy preparation of serial sections
T
________ is a cohesive agent used in double embedding for friable tissue or multiple fragments
Agar
Select: Mainly for producing whole organ sections / friable tissues
A) Agar
B) Gelatin
C) Ester Wax
D) Water-Soluble Waxes
B
T/F water-soluble waxes allow tissue to be embedded directly from water but can cause fragmentation due to violent diffusion currents
T
plastic embedding medium commonly used extensively for light microscopy?
Acrylic (Methyl Methacrylate - MMA)
OOOO: Plastic embedding medium
A) Epoxy
B) Polyester
C) Agar
D) Acrylic
C – not a plastic embedding medium
plastic embedding medium that reduces antigenicity but can be toxic and damage tissue
epoxy
_____ is a plastic embedding medium containing Bisphenol A (Araldite), or Glycerol (Epon), or Cyclohexene dioxide (Spurr)
Epoxy
T/F acrylic is a plastic embedding medium containing methyl methacrylate (MMA) and polyglycol methacrylic (GMA)
T
embedding mold consists of two L-shaped metal pieces that can be adjusted for size
Leuckhart’s Embedding Mold
*arranged on glass metal plate to form mold of desired size
molds for embedding which is used for routine work and are widely used
Leuckhart’s embedding mold
T/F Leuckhart’s embedding mold is commonly used for adjusting the size of tissue blocks and preparing serial sections
T
The _________ embedding mold consists of a series of interlocking plates, allowing multiple specimens to be embedded at once
Compound Embedding Unit
OOO: Compound Embedding Unit
A) Interlocking plates
B) Single tissue block output
C) Metal base for stability
D) Capability to embed multiple specimens at a time
B - designed to embed multiple specimens, not just a single block
embedding mold that is compatible with most commonly used processing and
storage systems
plastic embedding ring and base mold
material used to make Plastic Embedding Rings, known for their dimensional rigidity and compatibility with processing systems
premium-grade,
chemically inert, high-impact polystyrene
T/F Plastic embedding rings and base molds are reusable and used for precise positioning of histological tissues
T
_______ molds are metal molds of different sizes and depths used depending on the tissue or the laboratory’s needs
base molds
OOO: Pop-Out Embedding Mold
A) Reusable
B) Allows quick paraffin block retrieval
C) For single tissue block outcomes
D) Used for embedding multiple specimens
D - for single tissue block outcomes
T/F Disposable embedding molds like Peel-a-way molds are reusable and can be peeled off after the wax has solidified
False – disposable nga db
type of embedding mold that allows for direct placement of the tissue block in the microtome without trimming after peeling away the mold
Disposable Embedding Mold (Peel-a-way)
T/F Paper boats are made from thick paper or cardboard and allow for easy identification of tissue blocks
T
type of embedding mold made from thick paper or cardboard, allowing tissue blocks to be stored and easily identified
paper boat
T/F plastic ice trays are often used for embedding because they are easy to flex, making it easy to remove blocks.
T
embedding tool ideal for small fragmentary biopsies but may make blocks hard to remove
watch glasses
The inside of a plastic ice tray mold can be smeared with glycerin or liquid ________ to ease block removal
paraffin
One disadvantage of using test tubes for embedding is that it is often necessary to _______ the tube to remove the block
break
OOO: Plastic ice tray used in embedding
A) Easy to flex for block removal
B) Each compartment holds one block
C) Often used for tissue orientation
D) Requires regular trimming before use
does not require
T/F Test tubes are ideal for small and elongated specimens and often concentrate bone marrow at the bottom while causing slight damage.
F - no damage
embedding medium typically used for tissues intended for electron microscopy (EM)
Methacrylate Plastic Resin (Epon Resin)
t/f watch glasses are essential for smearing with glycerin to remove blocks more easily.
F -smearing with glycerin is not essential
T/F Low viscosity Nitrocellulose (LVN) is highly explosive.
T
Select: How to Embed - Swiss
A) Intestine
B) Long Tissue
C) Membrane
D) Tubular tissue
C
T/F Blocks are easily removed by smearing the inside of the mold with glycerin.
T
T/F Tissues should not reach the edges during embedding to prevent damage during sectioning.
T
orientation of tubular tissue, like the fallopian tube, during embedding
cross-sectionally (cut transversely)
when embedding skin, ensure that all layers of the skin are properly oriented so that the relationship between the _______ and the _______ is visible.
dermis, epidermis
T/F Endometrial curetting should be embedded off-center in the paraffin block
F - kept in center
long tissues should be embedded __________ to ensure the specimen is preserved properly.
diagonally
T/F when embedding, tissues should be surrounded by at least 2 mm of paraffin wax on all sides to prevent damage during sectioning
T
Select: Embedded with all layers visible in order
A) Intestine
B) Skin
C) Endometrial curetting
D) Tubular tissue
A - all seen in proper order
