Fixation (Part 2)

Question 1

Fixatives that do not bind or do not become part of the tissue

Answer 1

Non-additive fixatives

Question 2

Examples of Non-additive fixative

Answer 2

Acetone and Alcohol

Question 3

Fixatives that bind or become part of the tissue

Answer 3

Additive fixatives

Question 4

All fixatives are additives EXCEPT for

Answer 4

Acetone and Alcohol

Question 5

Types of fixatives as to ACTION

Answer 5

1. Microanatomical fixatives
2. Cytological fixatives
3. Histochemical fixatives

Question 6

Used to preserve parts of the cell such as nucleus and cytoplasm

Answer 6

Cytological

Question 7

Used to preserve nuclear chromatin or parts of the nucleus

Answer 7

Nuclear fixatives

Question 8

Examples of Nuclear fixatives (5)

Answer 8

Carnoy’s, Bouin’s, Newcomer’s, Heidenhain’s Susa, Flemmings with HAc

Question 9

Used to preserve cytoplasmic organelles such as mitochondria, golgi apparatus, etc.

Answer 9

Cytoplasmic Fixatives

Question 10

Examples of Cytoplasmic fixatives (4)

Answer 10

Regaud’s/Moller’s, Orth’s, Formalin with post chroming, Flemming’s without HAc

Question 11

Used to preserve the chemical components of tissues

Answer 11

Histochemical Fixatives

Question 12

Example of histochemical fixatives

Answer 12

Acetone (used for preserving enzymes)

Question 13

How to prepare 1 liter of 10% formalin

Answer 13

Combine 100mL of 37-40% formalin to 900mL of distilled water

Question 14

Disadvantage of formalin

Answer 14

Long time storage > has a tendency to precipitate

Question 15

This will prevent the precipitation of formaldehyde to white paraformaldehyde for prolong storage

Answer 15

10% methanol

Question 16

Mercuric chloride, chromate and lead fixatives are all under

Answer 16

Metallic fixatives

Question 17

Most common __ fixative that is excellent for trichrome staining and tissue photography. Contains mercuric chloride as the basic ingredient

Answer 17

Mercuric chloride fixatives

Question 18

Proposed as mercuric chloride substitute; also toxic to man

Answer 18

Zinc sulfate

Question 19

preserves liver, spleen, connective tissue, and nuclei

Answer 19

Zenker’s fluid

Question 20

preserves bone marrow

Answer 20

B5

Question 21

for tumor skin biopsies preservation

Answer 21

Heidenhain’s Susa

Question 22

preserves pituitary gland, bone marrow, spleen and liver

Answer 22

Helly’s fluid (Zenker formol or formol Zenker)

Question 23

All chromate fixatives contain

Answer 23

Potassium Dichromate

Question 24

preserves carbohydrate

Answer 24

1-2% chromic acid

Question 25

preserve lipids and mitochondria

Answer 25

3% potassium dichromate

Question 26

For mitochondria, RBC and colloid containing tissues

Answer 26

Regaud’s or Moller’s

Question 27

For Rickettsiae and other bacteria, tissue necrosis

Answer 27

Orth’s fluid

Question 28

Used to preserve acid mucopolysaccharide

Answer 28

Lead fixative

Question 29

Example of aldehyde fixatives

Answer 29

Glutaraldehyde and Formaldehyde/Formalin fixatives

Question 30

Used for Electron Microscopy; needs to be diluted because it cannot be used as concentrated

Answer 30

Glutaraldehyde

Question 31

Glutaraldehyde used for small tissue fragments or needle biopsies

Answer 31

2.5% solution

Question 32

Glutaraldehyde used for large tissue <4mm thick

Answer 32

4% solution

Question 33

• preserve CNS tissue and post mortem specimens
• This is a diluted form of formalin which uses NSS

Answer 33

10% formol saline

Question 34

• for tissues with iron pigments
• Same with 10% formalin EXCEPT that sodium phosphate as added as a buffer

Answer 34

10% Neutral Buffered Formalin

Question 35

Used for preserving lipids and neutral phospholipids

Answer 35

Formol corrosive (formol sublimate)

Question 36

Composition of formol corrosive

Answer 36

Formalin + Mercuric Chloride

Question 37

Used for sputum specimen and for microincineration technique

Answer 37

Alcoholic formalin (Gendres)

Question 38

This can be used also for sputum specimen

Answer 38

10% formalin

Question 39

Composition of Alcoholic formalin/Gendres

Answer 39

Ethyl alcohol + Glacial acetic acid + formalin

Question 40

regard as the smallest aldehyde but rapid/fast acting

Answer 40

Glyoxal

Question 41

Examples of Alcoholic fixative

Answer 41

Ethanol
Methanol
Isopropyl
Carnoy’s
Newcomer’s