LAB|midterm Flashcards

1
Q

Primary aim of fixation

A

Primary aim: preserve the morphological and chemical integrity of the cell in as life-like manner.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Secondary goal of fixation

A

harden and protect the tissue from the trauma of further handling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

fixed to structural proteins and thus rendered insoluble

A

Stabilizing proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

fixative becomes part of the tissue

A

Additive fixation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

fixative does not incorporate

A

Non-additive fixation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Duration of fixation of buffered formalin

A

24 h

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Hydrogen Ion Concentration

A

pH 6 and 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Fixative According to composition

A

i. Simple Fixative
ii. Compound Fixatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

types of Metallic Fixatives

A
  1. Mercuric Chloride
  2. Chromate Fixatives
  3. Lead Fixatives
  4. Heat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

made up of only one component substance.

A

Simple Fixative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

made up of two or more fixatives

A

Compound Fixative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

permits the general microscopic study of tissue structures

A

Microanatomical Fixatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

preserve the specific parts and particular microscopic elements of the cell itself

A

Cytological

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

preserve nuclear structures

A

Nuclear Fixative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

preserves cytoplasmic

A

Cytological Fixatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

preserve chemical contents of cells and tissues

A

Histochemical Fixatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Use mercuric chloride and potassium dichromate

A

LIPID FIXATION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

fixation for phospholipids

A

Baker’s formol calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

CARBOHYDRATE FIXATION

A

Alcoholic formaldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

PROTEIN FIXATION

A

Neutral buffered formol saline or formaldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

GLYCOGEN FIXATION

A

Rossman’s fluid or absolute alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

widely used ALDEHYDE FIXATIVES

A

Formaldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

white precipitation

A

paraformaldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Removal of precipitate is addition of 10% methanol

A

Formaldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  • preserves enzymes and proteins
  • fixation of CNS Tissues and General post-mortem tissues
A

10% Formol-Saline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  • preservation of surgical, post-mortem and research specimens
  • best fixative for iron-containing tissues
A

10% Neutral Buffered Formalin/Phosphate-Buffered Formalin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

preserves human brain, pH 7

A

10% Neutral Buffered Formalin/Phosphate-Buffered Formalin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q
  • routine post-mortem tissues
  • excellent in silver reticulum methods
  • fixes lipids, especially neutral fats and phospholipids
A

Formol-Corrosive (Formol Sublimate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q
  • immunoperoxidase studies on tissues
  • used for rapid diagnosis
  • good for preservation of glycogen and for micro- incineration
    -used to fix sputum, since it coagulate mucus
A

Alcoholic Formalin (Gendre’s Fixative)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q
  • two formaldehyde residues linked by 3C chains
  • used for enzyme histochemistry and electron microscopy
  • preserves plasma proteins
A

Glutaraldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q
  • most common metallic fixative
  • Tissues fixed with mixtures containing mercuric chloride (except Susa) contain black precipitates of mercury.
  • Routine fixative of choice for preservation of cell detail in tissue photography.
A

MERCURIC CHLORIDE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q
  • Renal tissues, Fibrin, Connective tissues and muscles
  • Black deposits may be removed by adding saturated iodine solution in 96% alcohol, the iodine being decolorized with absolute alcohol in the subsequent stages of dehydration.
A

MERCURIC CHLORIDE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q
  • Mercuric Chloride + Glacial Acetic Acid
  • fixing small pieces of liver, spleen, connective tissue and nuclei
  • may act as mordant
A

Zenker’s Fluid

34
Q
  • fixative for pituitary gland, bone marrow and blood containing organs such as spleen and liver.
  • preserves cytoplasmic granules
  • Brown pigments are produced if tissues are allowed tomore than 24 hours.
A

Zenker-formol (Helly’s solution)

35
Q
  • tumor biopsies especially of the skin
A

Heidenhain’s Susa Solution

36
Q

Lillie’s B-5 Fixative

A

bone marrow biopsies

36
Q
  • used in 1-2% aqueous solution
  • precipitates all proteins and adequately preserves carbohydrates.
A

Chromic Acid

36
Q
  • used in 3% aqueous solution
  • preserves lipids
  • preserves mitochondria
A

Potassium Dichromate

37
Q
  • Demonstration of chromatin, mitochondria, mitotic figures, Golgi bodies, RBC and colloid-containing tissues
  • Prolonged fixation gives out black deposits and can be removed by running tap water.
A

Regard’s (Muller’s) Fluid

37
Q
  • study of early degenerative proceses and tissue necrosis
  • demonstrates rickettsiae and other bacteria
  • preserves myelin
A

Orth’s Fluid

37
Q
  • used in 4% aqueous solution
  • recommended for acid mucopolysaccharides
  • fixes connective tissue mucin
  • forms insoluble lead carbonate due to prolonged standing which can be removed by filtration or adding acetic acid drop by drop
A

LEAD FIXATIVES

37
Q
  • Fixation of embryos and pituitary biopsies
  • Preserving soft and delicate structures (endometrial curettings)
  • yellow stain is useful for handling fragmentary biopsies.
  • collagen, elastic connective tissues
A

Bouin’s Solution

38
Q
  • Yellow color may be removed by treatment with another acid dye or lithium carbonate
  • excellent fixative for glycogen demonstration
  • suitable for Aniline stains
A

PICRIC ACID FIXATIVES

39
Q
  • Fixative for glycogen
  • Less messy than Bouin’s solution
A

Brasil’s Alcoholic Picroformal Fixative

40
Q
  • Precipitates chromosomes and chromatin materials
  • Essential constituent of most common compound nuclear fixatives
A

GLACIAL ACETIC ACID

41
Q
  • Ideal for small tissue fragments
  • Used as a fixative and dehydrating agent
A

ALCOHOLIC FIXATIVES

42
Q
  • fixing dry and wet smears, blood smears and bone marrow tissues
A

Methyl Alcohol

43
Q

fixing touch preparations

A

Isopropyl Alcohol 95%

44
Q

blood, tissue films and smears

A

Ethyl Alcohol

45
Q
  • fixing chromosomes, lymph node glands
  • fix brain tissue for diagnosis of rabies
A

Carnoy’s Fluid

46
Q
  • fixing mucopolysaccharides and other proteins
A

Newcomer’s Fluid

46
Q
  • Pale yellow powder which dissolves in water to form strong oxidizing solution.
    -fixes conjugated-fats and lipids permanently by making them insoluble during subsequent treatment with alcohol and xylene
    -helps preserve cytoplasmic structure
    -fixes myelin and peripheral nerves well
    -fixes materials for ultrathin sectioning in electron
A

OSMIUM TETRAOXIDE (OSMIC ACID)

46
Q

-an excellent fixative for nuclear structures
-permanently fixes fat

A

Flemming’s Solution

47
Q
  • Made up only of chromic and osmic acid
  • Removal of acetic acid from the formula serves to improve the cytoplasmic detail of the cell
A

Flemming’s solution without acetic acid

48
Q
  • incorporated into compound fixatives
    -precipitates proteins
    -marked swelling effect on tissues serves to counteract shrinkage produced by other fixatives
    -may be used as a weak decalcifying agent
A

TRICHLOROACETIC ACID

49
Q
  • Used at a cold temperature ranging from 5C to 4C
  • Recommended for the study-of water diff8usible enzymes especially phosphatases and lipases
A

ACETONE

50
Q
  • Involves thermal coagulation of tissue protein for rapid diagnosis
  • Employed for frozen tissue sections and bacteriologic smears
  • Destroys RBC
  • Dissolves starch and glycogen
A

HEAT FIXATION

51
Q
  • Process of replacing an already fixed tissue in a second fixative order
  • Usually with 10% formalin or 10% formol saline as primary fixative
A

SECONDARY FIXATION

52
Q

-form of secondary fixation whereby a primarily fixed tissue is placed in aqueous solution of 2.5- 3 % potassium dichromate for 24 hours to act as mordant for better staining effects

A

POST CHROMATIZATION

53
Q

-process of removing excess fixative from the tissue after fixation in order to improve staining and remove artifacts from the tissues

A

WASHING-OUT

54
Q

removes:
-excess chromates from tissues fixed in Kelly’s, Zenker’s, and Flemmings solutions
-excess formalin
-excess osmic acid

A

Tap water

55
Q

used to wash out excess amount of picric acid (Bouin’s solution)

A

50-70% alcohol

56
Q

used to remove excessive mercuric fixatives

A

Alcoholic iodine

57
Q

Types of Aldehyde

A
  1. Glutaraldehyde
  2. Formaldehyde
58
Q
  • vary according to structural and chemical components of the cells to be studied
  • may be done on fresh/preserved tissue
A

Fresh tissue examination

59
Q

selected tissue is immersed in watch glass containing NSS then carefully dissected/separated and examined under the microscope.

A

Teasing/Dissociation

60
Q

small pieces not more than 1 mm are placed in a slide and forcibly compressed with another slide or with a cover glass.

A

Squash Preparation/Crushing

61
Q

examining sections of sediments, whereby cellular materials are spread lightly over a slide by means of wire loop or applicator.

A

Smear Preparation

62
Q

two slides are used

A

Pull-Apart

63
Q

zigzag line

A

Streaking

64
Q

teasing mucous strands

A

Spreading

65
Q

cells are transferred to the slide

A

Touch Preparation

66
Q

Tissue is frozen with liquid nitrogen and a section is examined under the microscope.

A

Frozen Section

67
Q

PROCESSING OF TISSUES

A
  1. Fixation
  2. Dehydration
  3. Clearing
  4. Infiltration (Impregnation) Embedding
  5. Trimming
  6. Section-Cutting
    7.Staining
  7. Mounting
  8. Labelling
68
Q

fixing or preserving fresh tissue for examination

A

Fixation

69
Q

MAIN FACTORS INVOLVED IN FIXATION:

Temperature?

A

Formalin heated at 60C

70
Q

MAIN FACTORS INVOLVED IN FIXATION:

Thickness of section?

A

2cm2 for light microscopy

71
Q

MAIN FACTORS INVOLVED IN FIXATION:

Osmolality?

A

slightly hypertonic

72
Q

PRACTICAL CONSIDERATIONS OF FIXATION:

A
  1. Speed
  2. Penetration
  3. Volume
  4. Duration of Fixation
73
Q

Types of Lead Fixative

A

a. Picric Acid
b. Acetic Acid
c. Acetone
d. Alcohol
e. Osmium tetraoxide

74
Q

What are the cytological fixatives

A
  1. Nuclear fixative
  2. Cytological Fixative
  3. Histochemical Fixative