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HISTOPATHOLOGY (TopnotcherQT) > FIXATIVES ANB THEIR SPECIFIC PURPOSE/FUNCTION > Flashcards

FIXATIVES ANB THEIR SPECIFIC PURPOSE/FUNCTION Flashcards

memorization

1
Q

Mos widely used fixative of all

A

Formaldehyde (formalin)

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2
Q

Formalin is a saturated solution of ____ w/v formaldehyde in water

A

37-40% w/v

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3
Q

The usual 10% formalin used in fixation of tissues is a 10% solution of formalin, containing about ____% weight to volume of formaldehyde

A

4% weight to volume of formaldehyde

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4
Q

Formaldehyde fixation is performed at what temperature?

A

Room temperature

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5
Q

NOTE: Formaldehyde fumes are irritating to the nose and eyes and may cause ALLERGIC RHINITIS, SINUSITIS, EXCESSIVE LACRIMATION

A
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6
Q

Concentrated solutions of formaldehyde must _____________ since this might precipitate and cause violent explosions

A

MUST NEVER BE NEUTRALIZED

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7
Q

FORMALDEHYDE WASTES
1. Can be _____ by distillation or by drain disposal
2. Can be _____ by a commercial product
3. Can be _____ by a licensed waste hauler

A

FORMALDEHYDE WASTES
1. Can be RECYCLED by distillation or by drain disposal
2. Can be DETOXIFIED by a commercial product
3. Can be DISPOSED by a licensed waste hauler

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8
Q

Recommended for fixation of central nervous tissue and GENERALPOST-MORTEM tissues for histochemical examination

A

10% FROMOL SALINE

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9
Q

Formaldehyde fixative -The BEST GENERAL-PURPOSE TISSUE FIXATIVE

A

10% NEUTRAL BUFFERED FORMALIN

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10
Q

Formaldehyde is usually buffered at ________ with _______ buffer

A

Formaldehyde is usually buffered at pH 7 with PHOSPHATE buffer

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11
Q

In order to prepare 10% solution of formalin:

A

Mix 1 PART (100 mL) of 37-40% formaldehyde to 9 PARTS (900 mL) of distilled /tap water

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12
Q

Composition of 10% Neutral Buffered Formalin:

A
  1. Distilled/tap water - 900 mL (9parts)
  2. Formalin (37-40% formaldehyde solution) - 100 mL (1part)
  3. Sodium phosphate, monobasic, monohydrate - 4 grams
  4. Sodium phosphate, dibasic, anhydrous - 6.5 grams
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13
Q

Formalin is the fixative of choice for:

A
  • FATS
  • SURGICAL SPECIMENS
  • ENZYME HISTOCHEMISTRY
  • IMMUNOFLOURESCENCE
  • IMMUNOHISTOCHEMISTRY (IHC)
  • COLORED TISSUE PHOTOGRAPHY
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14
Q

Formalin is the BEST fixative for

A

NERVOUS SYSTEM

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15
Q

Formalin is the best fixative for tissues containing:

A

IRON PIGMENTS

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16
Q

Formaldehyde fixative recommended for ROUTINE POST-MORTEM tissues

A

FORMOL-CORROSIVE/ FORMOL-SUBLIMATE

**GENERAL Post-Mortem tissues - 10% FORMOL SALINE
**ROUTINE Post-Mortem tissues - FORMOL CORROSIVE/FORMOL-SUBLIMATE

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17
Q

Formaldehyde fixative used to fix SPUTUM since it coagulates mucus

A

GENDRE’s (ALCOHOLOC FORMALIN)

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18
Q

Formalin pigment; WHITE Crystalline precipitate due to prolonged storage

A

PARAFORMALDEHYDE

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19
Q

Removal of paraformaldehyde:

A
  • Removed by addition of 10% METHANOL or FILTRATION

*** Methanol is used as a preservative/stabilizer to retard formaldehyde and prevent its decomposition to formic acid or precipitation to paraformaldehyde

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20
Q

Prevention of paraformaldehyde:

A

Store in LOW temperature

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21
Q

Formalin pigmen; BROWNISH-BLACK pigment granules produced by unstable formaldehyde fixatives as a result of the reaction between formic acid and hemoglobin

A

ACID FORMALDEHYDE HEMATIN

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22
Q

Removal of Acid formaldehyde hematin

A
  1. Kardasewitsch’s method - specimen is placed in mixture of 70% ethyl alcohol and 30% ammonia water then wash with water
  2. Picric acid method - specimen is placed in saturated picric acid then wash with running water
  3. Alcoholic KOH (Potassium hydroxide)
  4. Lillie’s Method - specimen is placed in mixture of acetone, hydrogen peroxide and ammonia water then wash in 70% alcohol and water
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23
Q

Prevention of acid formaldehyde hematin:

A

Formalin is BUFFERED to a neutral pH of 7.0 with phosphate

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24
Q

Aldehyde fixative made up of TWO formaldehyde residues, linked by THREE carbon chains

A

GLUTARALDEHYDE FIXATVES

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25
Q

Glutaraldehyde fixatives are excellent fixative for ______________________, followed by secondary fixation in osmium tetroxide

A

ELECTRON MICROSCOPY

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26
Q

NOTE: GLUTARALDEHYDE is the PRIMARY, MOST WIDELY USED ADN EXCELLENT FIXATIVE FOR ELECTRON MICROSCOPY

A
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27
Q

Fixatives of ELECTRON MICROSCOPY

A
  1. GLUTARALDEHYDE
  2. Osmium tetroxide
  3. Paraformaldehyde
  4. Karnovsky’s (Glutaraldehyde + Paraformaldehyde)
  5. Zamboni fluid
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28
Q

How many hours is the fixation time of tissues for EM?

A

THREE (3) Hours is the fixation time of tissues for EM

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29
Q

Tissue fixation for EM is performed at what temperature:

A

0 to 4C (REF. TEMP)

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30
Q

Embedding medium for EM:

A

PLASTIC medium (such as Epoxy resin)

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31
Q

Type of microtome used for EM:

A

Ultrathin microtome

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32
Q

Knife to be used for EM:

A

Diamond or Glass knives

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33
Q

Stains for EM:

A
  1. LEAD CITRATE - BEST STAIN FOR EM
  2. Uranyl acetate
  3. Phosphotungstic acid
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34
Q

MOST COMMON METALLIC FIXATIVE; it permits brilliant metachromatic staining of cells:

A

MERCURIC CHLORIDE

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35
Q

Mercuric chloride is most commonly used metallic fixative recommended for fixing _____ biopsies

A

RENAL BIOPSIES

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36
Q

Mercuric chloride is the routine fixative of choice for preservation of:

A

CELL DETAIL IN TISSUE PHOTOGRAPHY

37
Q

NOTE:
Mercurial fixatives and reagents used in dezenkerization MUST NOT go through drain disposal

A
38
Q

Removal of black mercuric deposits:

A

Dezenkerization

39
Q

Mercuric deposits may be removed by immersing tissues in _______ solution prior to staining, through the process known as DEZENKERIZATION treated together with sodium thiosulfate

A

ALCOHOLIC IODINE

40
Q

MERCURIC CHLORIDE FIXATIVES:

A
  1. B-5 FIXATIVE
  2. HEIDENHAIN’S SUSA
  3. ZENKER’S FLUID
  4. ZENKER’S FORMOL (HELLY’S FLUID)

BHZZe
(ang mga tao sa Malaysia ay mga BHZZe ‘busy’)

41
Q

Mercuric chloride fixative that is used for cytology of BONE MARROW BIOPSIES

A

B-5 FIXATIVE

42
Q

Recommended mainly for TUMOR BIOPSIES OF THE SKIN and an excellent cytologic fixative

A

Heindenhain’s Susa

43
Q

The ONLY metallic fixative that DOES NOT produce mercuric chloride black deposits

A

Heidenhain’s susa

44
Q

Recommended for fixing SMALL PIECES OF LIVER, SPLEEN, CONNECTIVE TISSUE FIBERS and NUCLEI; Contains mercuric chloride, potassium dichromate, sodium sulfate, distilled water and GLACIAL ACETIC ACID

A

ZENKER’S FLUID

REMEMBER: Glacial acetic acid goods na goods sa nucleus, bad na bad sa cytoplasm

45
Q

Excellent microanaotomic fixative for PITUITARY GLAND, BONE MARROW and BLOOD-CONTAINING ORGANS such as spleen and liver; contains mercuric chloride, potassium dichromate, sodium sulfate, distilled water and STRONG FORMALDEHYDE (40%)

FIXATIVE OF CHOICE FOR INTERCALATED DISCS

A

ZENKER’S FORMOL (HELLY’S)

46
Q

Chromate fixatives:

A
  1. Chromic acid
  2. Regaud’s fluid (Muller’s)
  3. Orth’s fluid
  4. Potassium dichromate
47
Q

Chromate fixative that precipitates all proteins and adequately preserves CARBOHYDRATES

A

Chromic Acid

48
Q

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

A

Regaud’s fluid (Muller’s0

49
Q

Chromate fixative recommended for the study of early degenerative processes and tissue necrosis; demonstrates RICKETTSIAE and other bacteria

A

Orth’s fluid

50
Q

Chromate fixative for mitochondria; if acid is added, this fixes mucleoproteins

A

Potassium Dichromate

51
Q

4% aqueous solution of basic lead acetate; fixes tissue mucin and is recommended for ACID MUCOPOLYSACCHARIDE

A

LEAD FIXATIVE

NOTE:

LEAD - ACID MUCOPOLYSACCHARIDE
NEWCOMER’S - MUCOPOLYSACCHARIDE

52
Q

Excellent fixative for GLYCOGEN demonstration; YELLOW STAIN taken in by tissues prevents small fragments from being overlooked

A

PICRIC ACID FIXATIVE

53
Q

PICRIC ACID is highly explosive when _____

A

DRY

picric acid is highly explosive when dry therefore must be kept moist with distilled water or saturated alcohol during storage

54
Q

NOTE: PICRIC ACID can FIX, DIFFERENTIATE, and STAIN TISSUE ALL BY ITSELF!

A
55
Q

Picric acid fixatives:

A
  1. Bouin’s solution
  2. Brasil’s alcoholic picroformol
56
Q

Picric acid fixative recommended for fixation of EMBRYOS and pituitary biopsies; excellent in preserving soft and delicate structures such as endometrial curetting

A

BOUIN’S SOLUTION

NOTE:
BOUIN’S SOLUTIOON is NOT SUITABLE for fixing kidney structures, lipid and mucus

57
Q

Bouin’s solution contains:

A
  • FORMALDEHYDE
  • PICRIC ACID
  • GLACIAL ACETIC ACID

mnemonic:
anga mga BATA (EMBRYO) mahilig s FPG, ang probinsyano

F -formaldehyde
P - picric acid
g - glacial acetic acid

58
Q

BETTER and LESS MESSY than Bouin’s solutions; excellent fixative for GLYCOGEN

A

BRASIL’S ALCOHOLIC PICROFORMOL

59
Q

Yellow stain produced by picric acid can be removed though the use of:

A

TAP WATER

60
Q

Used in concentrations 70-100% because less concentrated solutions will produce lysis of cells

A

ALCOHOL FIXATIVES

61
Q

ALCOHOL FIXATIVES:

A
  1. 95% Isopropyl alcohol
  2. Carnoy’s fluid
  3. 70-100% Ethyl alcohol
  4. 100% Methyl alcohol
  5. Newcomer’s fixative

mnemonic: ICE MuNa bago ALCOHOL

62
Q

Used in fixing TOUCH PREPARATIONS for certain special staining procedures such as Wright-Giemsa

A

95% Isopropyl alcohol

63
Q

Considered to bethe “MOST RAPID FIXATIVE” with a fixation time of 1-3 hours; fixes and dehydrates at the same time

A

CARNOY’SFLUID

64
Q

Carnoy’s fluid is recommended for fixing:

A
  • Chromosomes
  • Urgent biopsies
  • Rabies (fix brain tissues for diagnosis for rabies)
  • Lymph glands

mnemonic = CURL/ kulot si Carnoy

65
Q

Carnoy’s fluid contains:

A
  • Glacial acetic acid
  • Absolute alcohol
  • Chloroform
66
Q

Used for histochemistry especially for enzyme studies; preserves nucleopeptides and nucleic acids and give the most DNA fragments for PCR

A

70-100% Ethyl Alcohol

67
Q

Excellent for fixing dry and wet smears, blood smears, and bone marrow smears

A

100% Methyl alcohol

68
Q

Recommended for fixing mucopolysaccharides and nuclear proteins; BOTH a NUCLEAR and HISTOCHEMICAL fixative

A

Newcomer’s fixative

REMEMBER:
LEAD - ACID MUCOPOLYSACCHARIDE
NEWCOMER’s - MUCOPOLYSACCHARIDE

69
Q

Major disadvantage of OSMIUM TETROXIDE:

A

NOT COMPATIBLE with H&E STAINING because it inhibits hematoxylin

NOTE:
- Osmium tetroxide can also cause CONJUNCTIVITIS or BLINDNESS
- Kept in dark colored, chemically clean bottle to prevent evaporation and reduction by sunlight
- Exposure to sunlight can also cause black deposits to buildup —> remedy: tap water

70
Q

Osmium tetroxide (osmic acid) fixatives:

A
  1. Flemming’s solution with glacial acetic acid
  2. Flemming’s solution without glacial acetic acid
71
Q

Most common osmium tetroxide fixative; Recommended for NUCLEAR section preparation; excellent fixative for nuclear structures such as CHROMOSOMES

A

Flemming’s solution WITH GLACIAL ACETIC ACID

REMEMBER: Glacial acetic acid; goods na goods sa Nucleus, bad na bad sa cytoplasm

72
Q

recommended for CYTOPLASMIC structures particularly the MITOCHONDRIA

A

Flemming’s solution WITHOUT Glacial acetic acid

REMEMBER: Glacial acetic acid; goods na goods sa nucleus, bad na bad sa cytoplasm

73
Q

OTHER SIGNIFICANT FIXATIVES TO REMEMBER:

  • GLACIAL ACETIC ACID
  • TRICHLOROACETIC ACID (TCA)
  • ACETONE
A

Glacial acetic acid
- normally used in conjunction with other fixatives to a compound solution
- Solidifies at 17C
- Precipitates chromosomes and chromatin materials; hence is useful in the study of NUCLEAR components of the cell
- It causes tissues to SWELL

Trichloroacetic acid (TCA)
- Used for the precipitation of proteins and nucleic acids
- A fixative and decalcifying agent; a ‘WEAK” decalcifying agent

Acetone
- used in fixing brain tissue for the diagnosis of rabies

74
Q

REMEMBER:
FIXATIVE and DEHYDRATING AGENT USED TO FIX BRAIN OF RABIES PATIENTS:

  • Carnoy’s fluid
  • Acetone
A
75
Q

IMPORTANT PROCEDURES RELATED TO FIXATION

  • Washing-out
  • Secondary fixation (Post-mordanting)
  • Post-chromatization
A
76
Q

Process of removing excess fixative from tissue after fixation to improve staining, and to remove artifacts from the tissues

A

WASHING-OUT

77
Q

Removes excess FORMALIN, OSMIUM TETROXIDE, CHROMATE FIXATIVE

A

TAP WATER

78
Q

Removes excess PICRIC ACID FIXATIVE (Boiun’s and Brasil’s)

A

50 to 70% ALCOHOL

79
Q

Removes excess MERCURIC CHLORIDE FIXATIVES

A

ALCOHOLIC IODINE

80
Q

Process of placing an already fixed tissue in a second fixative

A

SECONDARY FIXATION (POST-MORDANTING)

81
Q

A form of secondary fixation which uses a 2.5-3.0% potassium dichromate solution for 24 hours to act as mordant for better staining effects and to aid in cytologic preservation of tissues

A

POST-CHROMATIZATION

82
Q

PHYSICAL METHODS OF FIXATION

A
  1. Heat fixation
  2. Microwave fixation
  3. Cryopreservation (freeze-drying)
83
Q

SIMPLEST FORM of physical fixation; usually employed for FROZEN TISSUE SECTIONS and preparation of BACTERIOLOGIC SMEARS

A

HEAT FIXATION

84
Q

Works as a PHYSICAL AGENT to increase the movement of molecules and accelerate fixation

A

MICROWAVE FIXATION

Chief advantage: Tissue is heated through the block in a VERY SHORT TIME, thereby potentially allowing the study of cellular processes that proceed VERY RAPIDLY

Disadvantage: Microwaves generated by commercial ovens ONLY penetrate tissue to thickness of 10 to 15 mm

85
Q

A special way of preserving tissues by rapid freezing of fresh tissue 92mm thick) and subsequently removing ice water (desiccation) by a physical process of transferring the still frozen tissue block in a vacuum at a higher temperature

A

FREEZE-DRYING

86
Q

Freeze-drying temperatures

QUENCHING:
SUBLIMATION:

A

Freeze-drying temperatures

QUENCHING: -160 to -180C
SUBLIMATION: -30 to -40C

87
Q

Similar to freeze drying, the only variation is that the frozen tissue instead of being subjected to dehydration in an expensive vacuum drying apparatus, frozen tissue is fixed in a ROSSMAN’S FORMULA or in 1% acetone and dehydrated in absolute alcohol

A

FREEZE-SUBSTITUTION

88
Q

REMEMBER: FREEZE-SUBSTITUTION

Contents of ROSSMAN’S FORMULA:
- Picric acid
- 100% Ethanol
- Formalin

“PEF-peeve si ROSSMAN (rosmar) na mahilig magpalit pag nilalamigan”

A

HISTOPATHOLOGY (TopnotcherQT) (26 decks)

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