HPCT 311 > Fixation > Flashcards

Fixation Flashcards

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1
Q

`[2] Types of specimen samples obtain from surgical procedures.

A

Fresh samples
Fixed samples

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2
Q

For immediate diagnosis or evaluation.

[samples]

A

Fresh samples

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3
Q

Motion, mitosis and phagocytosis are to be observed.

[samples]

A

Fresh samples

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4
Q

Not permanent or its use is limited, are liable to develop changes that have been observed after death.

[samples]

A

Fresh samples

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5
Q

Detailed structure of cells because well preserved.

[samples]

A

Fixed samples

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6
Q

Avoid autolysis.

[samples]

A

Fixed samples

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7
Q

Often referred to as “cut – up”, involves a careful examination and description of specimen its- appearance, number of piece, and dimension.

A

Grossing

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8
Q

Patient information, Clinical History, Description of site of origin.

A

Request form

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9
Q

To reduce the risk of mislabeling, or mismatching.

A

Accessioned with a specific number (or barcode)

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10
Q

Specimen size for processing.

A

3X2 cm and 3-5 mm THICK

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11
Q

[6] Specimen types

A
  1. Excision specimens
  2. Incisional biopsy
  3. Punch biopsies
  4. Shave biopsies surface (usually skin)
  5. Curetting
  6. Core biopsies
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12
Q

[4] Methods of fresh tissue examination

A
  1. Teasing/Dissociation
  2. Crushing/ Squash preparation
  3. Smear preparation
  4. Frozen section
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13
Q

Normally used when a rapid diagnosis of a tissue is required.

[methods of fresh tissue examination]

A

Frozen section

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14
Q

Best for frozen section.

[freezing]

A

Unfixed tissue

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15
Q

Used to localize hydrolytic.

[freezing]

A

Fixed tissue

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16
Q

Without use of any chemical fixative.

A

Freeze drying

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17
Q

Rapid freezing (160°C)

A

Quenching

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18
Q

Removal of water in the form of ice (-40°C vacuum).

A

Sublimation

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19
Q

Frozen tissue is submerged to what formula?

A

Rossman’s formula

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20
Q

[5] Commonly used methods of freezing.

A
  1. Optimal cutting temperature
  2. Liquid nitrogen
  3. Isopentane
  4. Carbon dioxide gas
  5. Aerosol sprays
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21
Q

[2] Two methods of preparing frozen section

A
  1. Cold knife procedure
  2. Cryostat procedure
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22
Q

Almost any microtome can be used.

[methods of preparing frozen section]

A

Cold knife procedure

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23
Q

Cold microtome.

[methods of preparing frozen section]

A

Cryostat procedure

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24
Q

A refrigerated cabinet in which a modified
microtome is housed.

A

Cryostat

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25
OPTIMUM WORKING TEMPERATURE = -18 ° to -20 ° C [methods of preparing frozen section]
Cryostat procedure
26
Presently, the ROTARY MICROTOME is the type of choice. [methods of preparing frozen section]
Cryostat procedure
27
[12] Tissue processing
1. Accessioning 2. Fixation 3. Dehydration 4. Decalcification 5. Clearing/ Dealcoholization 6. Infiltration/Impregnation 7. Embedding 8. Trimming 9. Secretion/Microtomy 10. Staining 11. Mounting 12. Labelling
28
[2] Mechanism of action of fixative
1. Additive fixation 2. Non-additive fixation
29
Becomes part of the tissue by formation of cross links or complexes. Ex. Formalin, Hg, osmium tetroxide. [fixative]
Additive fixation
30
NOT incorporated in the tissue, stabilizes tissue by removing of the bound water. Ex. Alcoholic fixatives [fixative]
Non-additive fixation
31
[6] Factors involved in fixation
1. pH 2. Temperature 3. Thickness 4. Osmolality 5. Concentration 6. Time duration
32
Slightly hypertonic solution around 400- 450mOsm.
Osmolality
33
Rate of penetration: [practical consideration]
Formalin 1mm/hour.
34
Volume. [practical considerations]
10-25 times that of the tissue
35
maximum effectiveness. [practical considerations]
20:1
36
Osmium tetroxide. [practical considerations]
5-10:1
37
prolonged fixation (museum preparation) [practical considerations]
50-100: 1
38
[2] Types of fixative according to composition.
1. Simple fixative 2. Compound fixative
39
Are made up of only one component substance. [types of fixative acc to composition]
Simple fixtive
40
Are made up of two or more fixatives which have been added together. [types of fixative acc to composition]
Compound fixative
41
[3] Types of fixative acc to ACTION
1. Microanatomical fixative 2. Cytological fixative 3. Cytoplasmic fixative
42
[2] Cytological fixative
1. Nuclear fixative 2. Cytoplasmic fixative
43
Contains glacial acetic acid. (ex.Bouin’s fluid, Flemming’s fluid, Newcomers fluid, Carnoy’s fluid, Heidenhain’s SuSa (BFNCH) [cytololgical fixative]
Nuclear fixative
44
Helly’s fluid, Orth’s fluid, Regaud’s fluid, Flemming fluid without acetic acid, Formalin with post chroming (HORFF) [cytololgical fixative]
Cytoplasmic fixative
45
[3] Histochemical fixative
1. Lipid fixation 2. Carbohydrate fixation 3. Protein fixation
46
Fixatives containing mercuric chloride and potassium dichromate in cryostat section. [histochemical fixation]
Lipid fixation
47
Alcoholic fixative for glycogen (Rossman’s fluid or cold absolute alcohol) [histochemical fixation]
Carbohydrate fixation
48
Neutral buffered formalin.
Protein fixation
49
[8] Aldehyde fixatives
1. Formaldehyde 2. 10 % Formol saline 3. 10% Neutral Buffered Formalin (NBF) or PO4 buffered formalin 4. Formol corrosive 5. Glutaraldehyde 6. Karnovsky's paraformaldehyde - glutaraldehyde 6. Acrolein 7. Formol - calcium
50
[3] Metallic fixative
1. Mercuric chloride (BOSCHZZ) 2. Chromate fixatives 3. Lead fixative
51
[7] Mercuric chloride BOSCHZZ
1. B5 fixative 2. Ohlmacher's 3. Schaudinn's 4. Carnoy-Lebrun 5. Heidenhain Susa 6. Zenker 7. Zenker's formol
52
[4] Chromate fixatives (ROCP)
1. Regaud's (mollers) (molliflex) 2. Orth's fluid 3. Chromic acid 4. Potassium dichromate
53
HIGHLY EXPLOSIVE when dry.
Picric acid fixative
54
[2] Picric acid fixative
1. Bouin's 2. Brasil's alcoholic picroformol fixative
55
Recommended for fixation of embryos and pituitary biopsies. [picric acid fixative]
Bouin's
56
Excellent fixative for glycogen and less messy then Bouin’s solution (excellent). [picric acid fixative]
Brasil's alcoholic picroformol fixative
57
It is normally used in conjunction with other fixatives to form a compound solution.
Glacial acetic acid
58
Fixes & precipitates nucleoproteins, chromosomes, & chromatin material.
Glacial acetic acid
59
Solidifies at 17°C.
Glacial acetic acid
60
[6] Alcohol fixatives. (MEICAN)
1. Methyl alcohol 2. Ethanol 3. Isopropyl alcohol 4. Carnoy's fluid 5. Alcoholic formalin 6. Newcomer's
61
For fixing dry and wet smears (PBS and BM tissues. [alcohol fixatives]
Methyl alcohol
62
Simple fixative incorporated with compound fixatives for better results, preserves but does not fix glycogen (Disadvantage: polarization). [alcohol fixatives]
Ethanol
63
Fixing touch preparation. [alcohol fixatives]
Isopropyl alcohol
64
For fixing chromosomes, lymph glands and urgent biopsies (MOST RAPID;1-3 hours). [alcohol fixatives]
Carnoy's fluid
65
To preserve sputum. [alcohol fixatives]
Alcoholic formalin
66
For fixing mucopolysaccharides and nuclear proteins. Give better reaction in Fuelgen stain than Carnoys. [alcohol fixatives]
Newcomer's
67
[2] Osmium tetroxide (FF)
1. Flemmings solution 2. Flemming's solution without acetic acid
68
Most common chrome-osmium acetic acid fixative used (FIXATIVE & DECALCIFYING AGENT), permanently fixes fat, for nuclear structures (excellent). [osmium tetroxide]
Flemmings solution
69
(improve cytoplasmic details) – recommended for mitochondria. [osmium tetroxide]
Flemming's solution without acetic acid
70
[3] Fixation terminilogies (SPW)
1. Secondary fixation 2. Post - chromatization 3. Washing out
71
Process of placing an already fixed tissue in a second fixative. [fixation terminologies]
Secondary fixation
72
Fixation whereby a primarily fixed tissue is placed in Aqueos solution of 2.5-3% potassium dichromate. [fixation terminologies]
Post - chromatization
73
Removing excess fixative. [fixation terminologies]
Washing out
74
[3] Washing out (fixation terminologies)
1. Tap water (chromates) 2. 50-70% alcohol 3. Alcoholic iodine
75
[3] Factors affect fixation of tissues. (SAM)
1. size and thickness of tissue 2. Agitation 3. Moderate heat (37-56°)
76
Each specimen receives an what?
accession number
77
Each number is unique to that case and is.
NEVER reused.
78
SAC means
S (surgical) A (autopsy) C (cytology)
79
8o[4] Smear preparation [methods of fresh tissue examination]
Streaking Spreading Pull apart Touch preparation
80
pH: [factors involved in fixation]
6-8
81
[5] Temperature (ATERF) [factors involved in fixation]
1. Autotech (40°C) 2. Traditionally (RT) 3. EM and histochem (0-4°C) 4. Rapid examination (60°C) 5. For tissue w/ TB: (100°C)
82
Formalin. [concentration]
10%
83
Glutaraldehyde [concentration]
3%
84
Glutaraldehyde (IEM) [concentration]
0.25%
85
Primary fixation [time duration]
2-6 hours
86
EM fixation [time duration]
3 hours
87
Stock solution of Formaldehyde [aldehyde fixatives]
37-40%
88
Working solution of Formaldehyde. [aldehyde fixatives]
10%
89
For tumor biopsies esp of the skin. FT 3-12 hrs [mercuric chloride (BPSCHZZ)]
Heidenhain Susa
90
(fixing small pieces of liver,spleen, CT fibers and nuclei) FT: 12-24 hrs [mercuric chloride (BPSCHZZ)]
Zenker
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Fixative for pituitary gland, BM and blood containing organs. [mercuric chloride (BPSCHZZ)]
Zenker's formol
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Precipitates proteins. [trichloroacetic, acetone, heat fixation]
Trichloroacetic acid
93
Swelling effect 🡪 counteract shrinkage by other fixatives. [trichloroacetic, acetone, heat fixation]
Trichloroacetic acid
94
Weak decalcifying agent (softening effect) [trichloroacetic, acetone, heat fixation]
Trichloroacetic acid
95
Used at ice cold temperature from -5°C to 4°C. [trichloroacetic, acetone, heat fixation]
Acetone
96
For fixing BRAIN TISSUE (rabies diagnosis) [trichloroacetic, acetone, heat fixation]
Acetone
97
For diffusible enzymes such as phosphatases and lipases. [trichloroacetic, acetone, heat fixation]
Acetone
98
Microwave: 45-55°C [trichloroacetic, acetone, heat fixation]
Heat fixation
99
Thermal coagulation of tissue proteins. [trichloroacetic, acetone, heat fixation]
Heat fixation
100
For bacteriologic smears. [trichloroacetic, acetone, heat fixation]
Heat fixation
101
Failure to arrest early autolysis of cells. [cause]
Failure to fix immediately
102
Removal of substances soluble in fixing agent. [cause]
Wrong choice of fixatives
103
Presence of artifact pigments. [cause]
Incomplete fixation
104
Tissue are soft and feather like. [cause]
Incomplete fixation
105
Loss or inactivation of enzymes. [cause]
Wrong choice of fixative
106
Shrinkage and swelling of cells. [cause]
Overfixation
107
Tissue blocks are brittle and hard. [cause]
prolonged fixation
108
Best mounting media for cryostat. [methods of freezing]
Optimal Cutting Temperature (OCT)
109
Most rapid. [methods of freezing]
Liquid nitrogen
110
Cooled by liquid nitrogen. [methods of freezing]
Isopentane
111
Adequate for freezing small pieces of tissue EXCEPT muscle. [methods of freezing]
Aerosol sprays
112
For BM biopsies. FT: 1 ½ -2 hours. [mercuric chloride (BOSCHZZ)]
B5 fixative
113
[5] Steps in Mercuric chloride.
Water Iodine Water Sodium Thiosulfate Water
114
[5] Pigments
1. Acid formaldehyde hematin 2. Mercuric chloride pigment 3. Chromate pigment 4. Osmium tetroxide pigment 5. Crush artifact
115
Helly’s, Zenker’s, Flemming’s [washing out]
Tap water (chromates)
116
picric acid (Bouin’s solution) [washing out]
50 - 70 % alcoholic
117
mercuric fixatives. [washing out]
Alcoholic fixatives
118
Fixes CT mucin and is recommended for acid mucopolysaccharides. [metallic fixatives]
Lead fixatives
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to demonstrate chromatin, mitochondria, mitotic figures, golgi bodies, RBC. [chromate fixatives]
Regaud's
120
To study early degenerative processes and tissue necrosis, preserves myelin better. [chromate fixatives]
Orth's fluid
121
preserves CHO. [chromate fixatives]
Chromic acid
122
Preserves lipids and mitochondria (pH 4.5-5.2). [chromate fixatives]
Potassium dichromate
123
[2] Paraformaldehyde in Aldehyde Fixatives.
1. Paraformaldehyde 2. Acid Formaldehyde hematin
124
[5] Steps in Picric Acid Fixatives.
1. Picrates 2. Protein 3. Precipitate (water soluble) 4. 70% alcohol 5. Insoluble
125
Frozen section may lead to formation of?
Ice crystals
126
4% formalin or formol saline, acetone or formalin for cryostat section. [fixative abs]
Fixative for enzyme histochemistry
127
Glutaraldehyde, PtCl3, PtCl3– formalin (Zamboni’s), AuCl, Osmium tetroxide, 10% NBF = acceptable but not recommended. [fixative abc]
Fixatives for EM
128
KARNOVSKY’S PARAFORMALDEHYDE GLUTARALDEHYDE [fixative abc]
Fixative for electron histochemistry and electron immunocytochemistry.
129
pH of Potassium dichromate.
4.5 - 5.2
130
Example of Additive Fixation.
Formalin
131
Example of Non- additive fixation.
Alcoholic fixatives
132
Most important reaction for maintaining tissue morphology. [fixation/preservation]
Stabilization of proteins
133
To harden and protect the tissue from the trauma of further handling. [fixation/reservation]
Secondary aim
134
To preserve the morphologic and chemical integrity of the cell in as life-like manner as possible. [fixation/preservation]
Primary aim
135
Process of preserving cells and tissue constituents. [fixation/preservation]
First and most critical step
136
The tissue is preserved by preventing degeneration, putrefaction, decomposition and distortion. [fixation/preservation]
First and most critical step
137
Diluted in 10% NaCl. [aldehyde fixatives]
10 % formol saline
138
For routine post mortem tissues. [aldehyde fixatives]
Formol corrosive
139
w/ HgCl2. [aldehyde fixatives]
Formol corrosive
140
Mixture w/ formaldehyde/formaldehyde. [aldehyde fixtatives]
Acrolein
141
Lipids (frozen section] [aldehyde fixatives]
Formol-calcium
HPCT 311
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