Infiltration & Embedding Flashcards
(129 cards)
1
Q
Used for bones and brain specimens
A
Paraplast
2
Q
A substitute for paraffin wax that is used for infiltrating eye specimens?
A
Bioloid
3
Q
Product of paraffin with rubber
A
Tissue mat
4
Q
Eliminates dehydration and clearing process
A
Carbowax
5
Q
Uses 70-80% alcohol for storage
A
Wet Celloidin Method
6
Q
Melting point of 56-58 °C
A
Embeddol
7
Q
Method of paraffin wax infiltration that uses Autotechnicon
A
Automatic Processing
8
Q
Most rapid method of paraffin wax infiltration
A
Vacuum Embedding
9
Q
Removes clearing agent and fills up cavities
A
Infiltration
10
Q
Requires 4 changes of wax at 15 minutes interval in order to insure complete removal of the clearing agent from the tissue
A
Manual Processing
11
Q
T or F. Prolonged process of paraffin wax infiltration method may cause excessive shrinkage and tissue hardening
A
True
12
Q
Melting point for routine work
A
56°C
13
Q
a.k.a. COLLODION
A
Celloidin Infiltration
14
Q
Harder than paraffin and requires heavy duty type of microtome (e.g. sliding or sledge type microtome)
A
Ester wax
15
Q
Melting point 46-48°C
A
Ester wax
16
Q
Water soluble wax
A
Carbowax
17
Q
Another form of celloidin soluble in equal concentration of ether and alcohol; highly explosive
A
Low Viscosity Nitrocellulose (L.V.N.)
18
Q
Mixture of highly purified paraffin and synthetic plastic polymer
A
Paraplast
19
Q
Combination of chloroform and cedarwood oil
A
Components of Gilson’s mixture
20
Q
Prevents growth of molds
A
1% phenol
21
Q
Substitue for paraffin wax that is used for enzyme histochemistry
A
Carbowax
22
Q
Remedy when Carbowax is used?
A
Add soap to water or 10% polyethylene glycol 900
23
Q
Commonly used embedding medium
A
Paraffin wax
24
Q
Tissue infiltrated with this tends to crack
A
Low Viscosity Nitrocellulose (L.V.N.)
25
What to add in Low Viscosity Nitrocellulose (L.V.N.) to prevent from tissues in cracking?
Add Plasticizers: OLEUM RICINI & CASTOR OIL
26
Uses Gilson’s Mixture for storage
Dry celloidin
27
Methods of Celloidin Infiltration for infiltrating eye specimens
Dry Celloidin
28
Methods of Celloidin Infiltration for infiltrating bones, large brain sections, teeth, and whole organs
Wet Celloidin Method
29
Difficult to float out when this is used
Carbowax
30
No longer requires clearing, only dehydration
Ester wax
31
Concentration is 4-6% for 5-7 days
Medium Celloidin
32
Consist of 2 L-shaped strips of heavy brass or metal arranged on a flat metal plate and which can be moved to adjust the size of the mold to the size of the specimen
Leuckhart’s Embedding Mold
33
Recommended only for frozen sections and histochemical and enzyme studies
Gelatin Infiltration
34
Concentration is 2-4% for 5-7 days
Thin Celloidin
35
Used if there is need to be embed more than 1
specimen
Compound embedding unit
36
It is equipped with a warm plate to manage the impregnated specimen, and a cold plate at -5°C for rapid solidification of the block
Tissue Tek
37
Consist of a special stainless steel base mold fitted with a plastic embedding ring, which later serves as the block holder during cutting
Plastic embedding rings and base molds
38
Cutting off excess paraffin wax to form a 4-sided prism
Trimming
39
Concentration is 8-12% for 3-5 days
Thick Celloidin
40
A disposable mold that can produce perfect block even without trimming
Peel-Away
41
Temperature of melted paraffin used for embedding
5-10° above its melting point
42
This is done when we infiltrate using celloidin then embedding using paraffin wax
Double-Embedding
43
T or F. Inadequate process in paraffin wax infiltration method may cause retention of clearing agent
True
44
It is more rapid because it is heat generated, constant agitation (make the processing time shorter)
Automatic Processing
45
Recommended for urgent biopsies, for delicate tissues such as lungs, brain, connective tissues, decalcified bones, eyes, spleen and CNS
Vacuum Embedding
46
Carried out using paraffin wax infiltration and an oven
Manual Processing
47
NOT FOR fatty tissue because we need to apply heat (fats will dissolved)
Paraffin Wax Infiltration Method/Paraffin processing
48
It is soluble to 95% ethyl alcohol
Ester wax
49
For tissue with large and hallow cavities that tends to collapse
Celloidin Infiltration Method
50
Does not add heat so the process is slow
Nitrocellulose Method (Low Viscosity Nitrocellulose)
51
Tissue for processing should be 2-3mm thick
Gelatin Infiltration Method
52
Embedding for EM
Plastic (Resins) Embedding
53
T or F. To allow solidification of block either place the preparation inside the refrigerator at -5° or immerse it in cold water
True
54
This is recommended for busy routine laboratories
Plastic ice trays
55
For extremely hard tissues
Plastic (Resins) Embedding
56
Are made up of esters of acrylic or methacrylic acid, and are used extensively for light microscopy (i.e.,MMA,GMA)
Acrylic plastics
57
Made up of a carefully balanced mixture of epoxy plastics, catalysts and accelerators
Epoxy Embedding Plastics
58
Is the process whereby the clearing agent is completely removed from the tissue and replaced by a medium that will completely fill all the tissue cavities and give a firm consistency to the specimen
Impregnation (Infiltration)
59
Is the process by which the impregnated tissue is placed into a precisely arranged position in a mold containing a medium which is then allowed to solidify
Embedding (Casting or Blocking)
60
It is solid at room temperature but melts at temperatures up to about 65°C or 70°C
Paraffin Wax
61
3 ways by which paraffin wax impregnation and embedding of tissues may be performed
1. By manual processing
2. By automatic processing
3. By vacuum embedding
62
Involves wax impregnation under negative atmospheric pressure inside an embedding oven
Vacuum Embedding
63
Melting point of 56-57°C
Paraplast
64
Synthetic wax substitute similar to Paraplast
Embeddol
65
Substance added to proprietary blends of plastic polymer paraffin waxes
Dimethyl sulphoxide (DMSO)
66
Are plastic polymers, mostly polyethylene glycols
Water Soluble Waxes
67
T or F. During the winter, 54 to 56oC Paraplast may be used if the tissue is cut in a cool room.
True
68
A polyethylene glycol containing 18 or more carbon atoms, which appears solid at room temperature
Carbowax
69
Reduces infiltration times and facilitates thin sectioning
Dimethyl sulphoxide (DMSO)
70
No heat is required, and the resultant block has a rubbery consistency which gives good support to the tissues
Celloidin Impregnation
71
Is more explosive than celloidin and should therefore be handled with care
Low Viscosity Nitrocellulose (L.V.N.)
72
Is rarely used except when dehydration is to be avoided and when tissues are to be subjected to histochemical and enzyme studies
Gelatin Impregnation
73
Volume should be at least 25 times the volume of the tissue
Gelatin Impregnation
74
Is made up of a series of interlocking plates resting on a flat metal base, forming several compartments
Compound embedding unit
75
A disposable thin plastic embedding molds, available in 3 different sizes, are simply peeled off one at a time, as soon as the wax has solidified
Peel-Away
76
Are normally utilized for embedding celloidin blocks but are equally useful for paraffin wax blocks
Paper Boats
77
Can be used to control the rate or evaporation of the solvent
Bell jars
78
Is the process by which tissues are first embedded or fully infiltrated with a supporting medium such as agar or nitrocellulose, then infiltrated a second time with paraffin wax in which they are subsequently embedded.
Double-Embedding
79
Recommended for making small sections of celloidin blocks
Double-Embedding
80
Can be obtained pure, have very low viscosity, and infiltrate fastest
Cyclohexene dioxide-based plastics (Spurr)
81
Cause sensitization if absorbed by skin or inhalation
Epoxy resins
82
The polar water soluble, 2-hydroxyethyl methacrylate, is commonly known as
"Glycol methacrylate", or GMA
83
Is added to the plastic as a catalyst that decomposes to form phenyl radicals acting as an active site for the polymerization of acrylics
Benzoyl Peroxide
84
Widely used because of its hardness as the ideal embedding medium for undecalcified bone and is widely used for bone histomorphometry and bone marrow hematopathology
Methyl methacrylate (MMA)
85
Can easily and completely be removed from tissue sections, which results in superior staining characteristics and excellent morphological detail.
Methyl methacrylate (MMA)
86
Infiltration is slow, partly because the epoxy plastic itself is a large molecule
Bisphenol A (Araldite)
87
Has a lower viscosity but are often sold as mixtures of isomers
Glycerol (Epon)
88
Is a Low Viscosity mixture which provides rapid infiltration of tissues
Spurr’s Resin
89
This resin is compatible with ethanol so no change to propylene oxide is needed prior to infiltration
Spurr’s Resin
90
Polymerization at 60°C is recommended in
Spurr’s Resin
91
They are hydrophobic and subsequent oxidation by peroxide to correct this may produce tissue damage (disadvantage)
Epoxy plastics
92
The components of many epoxy plastics are toxic and one of its components is known to be carcinogenic
Vinyl cyclohexane dioxide (VCD)
93
They have the advantage of being cheap and easy to make
Paper boats
94
Is a polycrystalline mixture of solid hydrocarbons produced during the refining of coal and mineral oils
Paraffin wax
95
It facilitates complete removal of transition solvents, and prolongs the life of wax by reducing solvent contamination
Vacuum Embedding
96
It is less brittle and less compressible than Paraplast
Embeddol
97
It is used as an embedding medium for delicate specimens and frozen tissue sections because it prevents fragmentation of tough and friable tissues when frozen sections are cut
Gelatin Impregnation
98
It is water-soluble, and does not require dehydration and clearing, although fixatives (such as 10% formalin) should still be washed out by running water whenever indicated
Gelatin Impregnation
99
It has a low melting point and does not cause over-hardening of tissues by heating
Gelatin Impregnation
100
Each compartment may be utilized for embedding one tissue block, which may then be removed by bending the plastic tray once the wax has solidified or by smearing the inner mold with glycerin or liquid paraffin before embedding
Plastic Ice Trays
101
They provide easy and accurate identification of specimen, thereby avoiding confusion and interchange of tissue blocks
Paper Boats
102
Can be cut with glass or diamond knives
Thin sections of polymerized GMA
103
Does not need to be water-free and indeed it works best with at least some water present
Glycol methacrylate (GMA)
104
It forms only non-crosslinked straight chains on polymerization and therefore requires no hardener
Glycol methacrylate (GMA)
105
T or F. Ideally, an infiltrating and embedding medium should be expensive.
False. Inexpensive
106
T or F. Ideally, an infiltrating and embedding medium should be soluble in processing fluids.
True
107
T or F. Ideally, an infiltrating and embedding medium should be heterogenous.
False. Homogenous
108
T or F. Ideally, an infiltrating and embedding medium should be suitable for sectioning and ribboning.
True
109
T or F. Ideally, an infiltrating and embedding medium should be easy to handle.
True
110
T or F. Ideally, an infiltrating and embedding medium should be non-toxic, translucent or transparent; colorless and odorless.
True
111
T or F. Ideally, an infiltrating and embedding medium should be stable and capable of flattening after ribboning.
True
112
T or F. Ideally, an infiltrating and embedding medium should be molten between 30°C and 60°C.
True
113
The simplest, most common and best embedding medium used for routine tissue processing
Paraffin
114
What temperature of the wax is used when the laboratory temperature is between 15-18°C?
The melting point of wax to be used should be between 50 and 54°C
115
What temperature of the wax is used when the laboratory temperature is ranging from 20-24°C?
Paraffin wax with a melting point of 54-58°C
116
Only 2- 3 changes of wax are required to remove the clearing agent and properly impregnate the specimen (what process)
Automatic Processing
117
Requires a vacuum infiltrator or embedding oven, consisting of wax baths, fluid trap and vacuum gauge, to which a vacuum of up to 760 mm Hg is applied using a water or mechanical pump.
Vacuum infiltration
118
Consists of a flat-bottomed heavy brass chamber covered with a heavy glass lid resting on a wide and thick rubber valve which produces an airtight seal when the chamber is being used
Vacuum Embedding Oven
119
Temperature is maintained at 2°C to 4°C above the MP of the wax
Vacuum Embedding
120
T or F. Wax that has been trimmed away from the impregnated tissue may be melted and filtered for future use, with a coarse filter paper (e.g. Green’s No. 904)
True
121
Paraffin wax are only used how many times?
2
122
It is more elastic and resilient than paraffin wax thereby permitting large dense tissue blocks such as bones and brain to be cut easily with the same result as in double embedding
Paraplast
123
T or F. During the summer it may be necessary to use 60 to 63°C, although this is to be avoided if possible in order to not to "cook" the tissue.
True
124
Is a purified form of nitrocellulose soluble in many solvents, suitable for specimens with large hollow cavities which tend to collapse, for hard and dense tissues such as bones and teeth and for large tissue sections of the whole embryo
Celloidin
125
T or F. In celloidin, disadvantages include inability to cut thin sections, storage of blocks in alcohol and speed of technique (which can take several weeks or months)
True
126
What are the 2 methods to allow solidification of block?
a) Place the preparation inside the ref at -5°
b) Immerse it in cold water
127
Product of embedding?
TISSUE BLOCK
128
What embedding uses High Resolution Light Microscopy (tissue sections thinner than the usual 4-6 μm, such as renal biopsies a n d bone marrow biopsies)
Plastic (Resins) Embedding
129
Were originally introduced for electron microscopy in the mid- 1950s, but have been superseded by more superior epoxides, and are now seldom used.
Polyester plastics
