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HistoPathology > [M] Week 8: Gross Room / Surgical Cut- up - Part 2 > Flashcards

[M] Week 8: Gross Room / Surgical Cut- up - Part 2 Flashcards

(49 cards)

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1
Q

MIXTURE OF FIXATIVES

two aldehyde fixative mixtures have been particularly useful for electron cytochemistry

A

KARNOVSKY’S PARAFORMALDEHYDEGLU ARALDEHYDE SOLUTION

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2
Q

MIXTURE OF FIXATIVES

another aldehyde which has been introduced as a mixture
with glutaraldehyde or formaldehyde

A

ACROLEIN

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3
Q

ALDEHYDE FIXATIVES

  • 10% Formalin
  • usual fixation time 24 hrs
  • one of the most widely used
    ○ compatible with many stains, penetrates tissues well

Disadvantages:
- irritating fumes and upon contact to skin
- forms pigment granules (precipitates may be removed by filtration or addition of 10% methanol)
- unsuitable for electron microscopy

A

Formaldehyde (Formalin)

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4
Q

ALDEHYDE FIXATIVES

  • saturated formaldehyde diluted to 10% with NaCl
  • recommended for fixation of CNS & general post-mortem tissues for histochemical examination
  • slow fixative → >24 hrs
A

10% Formal-Saline

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5
Q

ALDEHYDE FIXATIVES

  • recommended for preservation and storage of surgical, post-mortem & research specimen
  • prevents precipitation of pigments (Commonly used by laboratories)
  • best fixative for tissues containing iron pigments and elastic fibers
  • 10% solution with sulfate or phosphate
A

10% Neutral Buffered Formalin or Phosphate-Buffered Formalin

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6
Q

ALDEHYDE FIXATIVES

  • recommended for routine post-mortem tissues or autopsy
  • excellent for many staining procedures including silver reticulum methods
A

Formol-Corrosive (Formol-Sublimate)

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7
Q

ALDEHYDE FIXATIVES

  • can be used for rapid diagnosis, fixes & dehydrates at the same time
  • good for the preservation of glycogen & for micro incineration
    technique
  • fix sputum
A

Alcoholic Formalin (Gendre’s) Fixative

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8
Q

ALDEHYDE FIXATIVES

  • Like buffered glutaraldehyde, followed by secondary fixation in osmium tetroxide is satisfactory for electron microscopy
  • 2-5% for small tissue fragments
  • 4% for* larger tissues*
  • Recommended for enzyme histochemistry and electron microscopy
A

Glutaraldehyde

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9
Q

Enumerate the ALDEHYDE FIXATIVE

A
  1. Formaldehyde (Formalin)
  2. 10% Formal-Saline
  3. 10% Neutral Buffered Formalin or Phosphate-Buffered Formalin
  4. Formol-Corrosive (Formol-Sublimate)
  5. Alcoholic Formalin (Gendre’s) Fixative
  6. Glutaraldehyde
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10
Q

Enumerate the Metallic Fixatives

A
  1. Mercuric Chloride
  2. Zenkers Fluid
  3. Zenker-Formol (Helly’s Solution)
  4. Heidenhains Susa Solution
  5. B-5 Fixative
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11
Q

METALLIC FIXATIVES

  • Most common metallic fixative (5 7% aqueous solution)
  • Mercury deposits are removed from deparaffinized sections before staining, by treating with 0.5% iodine solution in 70% ethanol for 5-10 minutes
  • Routine fixative of choice for preservation of cell detail in tissue photography
A

Mercuric Chloride

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12
Q

METALLIC FIXATIVES

  • with glacial acetic acid → prevent turbidity & formation of dark precipitate
  • recommended for fixing small pieces of liver, spleen, connective tissue fibers & nuclei
  • recommended for trichrome staining
  • De-zenkerization is performed by adding alcoholic iodine
A

Zenkers Fluid

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13
Q

METALLIC FIXATIVES

  • microanatomic fixative for pituitary gland, bone marrow & blood containing organs
  • It also produces pigments that can be removed by saturated alcoholic picric acid or NaOH
A

Zenker-Formol (Helly’s Solution)

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14
Q

METALLIC FIXATIVES

  • recommended mainly for tumor biopsy, especially skin
  • excellent cytologic fixative
A

Heidenahain’s susa solution

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15
Q

METALLIC FIXATIVES

Bone marrow biopsies

A

B-5 Fixative

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16
Q

Enumerate the CHROMATE FIXATIVES

A
  1. 1-2% Chormic acid
  2. 3% Potassium Dichromate
  3. Regard’s (mueller’s) fluid
  4. Orths Fluid

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17
Q

CHROMATE FIXATIVES

recommended for demonstration of chromatin, mitochondria,
mitotic figures, Golgi bodies, RBC, and colloid-containing
tissues

A

Regard’s (mueller’s) fluid

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18
Q

CHROMATE FIXATIVES

  • recommended for study of early degenerative processes & tissue necrosis
  • demonstrates Rickettsiae & other bacteria
  • preserves myelin better than buffered formalin
A

Orth’s Fluid

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19
Q

Fixative

In 4% aqueous solution is recommended for acid mucopolysaccharides
- It fixes connective tissue mucin
- It takes up CO2 to form insoluble lead carbonate removed by filtration or adding acetic acid

A

Lead Fixatives

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20
Q

Fixative

Enumerate the PICRIC ACID FIXATIVES

Study These Flashcards
A
  1. Bouin’s Solution
  2. Brasils’s Alcoholic Picroformol Fixative
21
Q
  • Excellent fixative for glycogen demonstration
  • Yellow color – removed by treatment with another acid dye or lithium carbonate
Study These Flashcards
A

Picric Acid Fixatives

22
Q

Picric Acid Fixatives

  • Recommended for embryos & pituitary biopsies
  • Excellent fixative for preserving soft & delicate tissues
  • Preferred fixative for tissues to be stained by Masson’s trichrome for collagen, elastic, or connective tissue
Study These Flashcards
A

Bouin’s solution

23
Q

Picric Acid Fixatives

  • Better and less “messy” than Bouin’s solution
  • Excellent fixative for glycogen
Study These Flashcards
A

Brasils’s Alcoholic Picroformol Fixative

24
Q
  • Normally used in conjunction with other fixatives (A compound fixative)
  • Solidifies at 170C
  • Very useful in the study of nuclear components of the cell
  • Causes tissue to swell which is used to counteract the shrinkage produced by other components (mercury)
  • Contraindicated for cytoplasmic fixation
Study These Flashcards
A

Glacial Acetic Acid

25
- May be both as a **fixative & dehydrating agent** - Excellent for **glycogen demonstration** - Contraindicated when lipids are to be studied
Alcohol Fixatives
26
Enumerate the Alcohol Fixatives
1. 100% Methyl Alcohol 2. 95% Isopropyl Alcohol 3. 70-100% Ethyl Alcohol 4. Carnoy's Fluid 5. Newcomer's Fluid
27
# ALCOHOL FIXATIVES Excellent for fixing dry & wet smears, blood smears & bone marrow tissues
100% METHYL ALCOHOL
28
# ALCOHOL FIXATIVES Used for fixing touch preparations, for certain special staining procedures such as Wright-Giemsa
95% ISOPROPYL ALCOHOL
29
# ALCOHOL FIXATIVES Used as a simple fixative but more frequently incorporated into compound fixatives
70%-100% ETHYL ALCOHOL
30
# ALCOHOL FIXATIVES - Recommended for fixing chromosomes, lymph glands & urgent biopsies - Considered to be the **most rapid fixative** - Also used to fix **brain tissue for diagnosis of rabies **
CARNOY’S FLUID
31
# ALCOHOL FIXATIVES - Recommended for fixing mucopolysaccharides and nuclear proteins - Acts both as **nuclear & histochemical fixative**
NEWCOMER’S FLUID
32
- Fixes conjugated fats & lipids permanently - Used extensively for neurological tissues - Adequately fixes electron microscopy - **Poor penetration.** The tissue should only be 2-3mm thick - Addition of saturated aqueous mercuric chloride will prevent its reduction with the formation of black deposits
Osmium Tetroxide (Osmic Acid)
33
Enumeratre the Osmium Tetroxide (Osmic Acid) Fixatives
1. Flemmings Solution 2. Flemmings solution without acetic acid
34
- **Most common** chrome-osmium acetic acid fixative - Excellent for nuclear structures - Permanently fixes fat
FLEMMING’S SOLUTION
35
# Osmium Tetroxide (Osmic Acid) Recommended for cytoplasmic structures, particularly **mitochondria**
FLEMMING’S SOLUTION WITHOUT ACETIC ACID
36
# Fixative - Precipitates proteins & poor penetrating agent - A **weak decalcifying agent** with softening effect on dense fibrous tissues (Causes marked swelling effect on tissues serve to counteract shrinkage produced by other fixatives) - Sometimes incorporated into compound fixatives
TRICHLOROACETIC ACID
37
# Fixative - Used it at ice cold temp from – **5 deg C to 40 deg C ** - Study of water-diffusible enzymes especially phosphatases & lipases - Fixing brain tissues for diagnosis of rabies - Dissolves fat - Preserves glycogen poorly
Acetone
38
# Fixative - Thermal coagulation of proteins - Suitable for frozen tissue sections (Fresh tissue is used. If we need to fix, it should be heat-fixed.) - Preparation of bacteriologic smears - Produces considerable tissue shrinkage & distortion - Destroys RBC - Dissolves starch and glycogen
Heat Fixation | Heat fixation should be used with precaution
39
- Placing an already fixed tissue into a **second fixative** - **Before dehydration** & on **deparaffinized section** before staining ○ Facilitate & improve the demonstration of particular substances ○ Special staining techniques ○ Ensure further & complete hardening and preservation of tissues
Secondary Fixation
40
- Form of secondary fixation - A primarily fixed tissue is placed in **2.5 to 3% potassium dichromate for 24 hours** ○ Act as mordant for better staining effects ○ Aid in cytologic preservation of tissues
Post-Chromatization
41
**Removing excess fixative** to improve staining and remove artifacts Several solutions may be used by submerging specimen in: - tap water or running waterr - 50-70% alcohol - alcoholic iodine
Washing out
42
Improper Fixation causes?
- Autolysis - Removal of substances; loss or inactivation of enzymes - Artifacy pigments - Soft & feather-like - Brittle & hard
43
# IMPROPER FIXATION Match 1. Autolysis 2. Removal of substances; loss or inactivation of enzymes 3. Artifacy pigments 4. Soft & feather-like 5. Brittle & hard A. Wrong choice of fixative B. Delay fixation or insufficient fixative, For large tissues in small containers , Solid organs not serially cut, Hollow organs that float C. Incomplete fixation D. Over fixation E. Incomplete washing
1. B 2. A 3. E 4. C 5. D
44
- Eliminated or reduced by fixation in **phenol formalin** - Use of neutral buffered formalin and phenol formalin almost completely stops the formation of formalin pigment
Fixation Artificats
45
# FIXATION ARTIFACTS Partial coagulation of partially fixed protein by ethanol or incomplete wax impregnation
CRUSH ARTIFACT
46
# FIXATION ARTIFACTS - used to accelerate staining, decalcification, immunohistochemistry & EM - Blocks are placed in a microwave ○ Alternative: regular kitchen microwave ○ 450 watts, 550C for 1.5 to 4 minutes - Useful in preserving neurochemical substances, such as acetylcholine - Rapid fixation - Reduces time taken for immunohistochemistry (IHC) and in-situ hybridization (ISH)
Microwave Technique
47
Enumerate the IMMUNOFLUORESCENCE AND IMMUNOPEROXIDASE TECHNIQUES
1. Enzyme Histochemistry 2. Electron Microscopy
48
# IMMUNOFLUORESCENCE AND IMMUNOPEROXIDASE TECHNIQUES - To preserve the maximum enzyme activity at its original localization, while also preserving structural integrity - 4% Formaldehyde or Formal saline - Acetone or Formaldehyde for fresh frozen cryostat sections
Enzyme HIstochemistry
49
# IMMUNOFLUORESCENCE AND IMMUNOPEROXIDASE TECHNIQUES - Osmium tetroxide - Glutaraldehyde - Paraformaldehyde - Karnovsky’s paraformaldehyde-glutaraldehyde
Electron Microscopy

HistoPathology (22 decks)

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