FIXATION

Question 1

Fixation is also known as ___________

Answer 1

PRESERVATION

Question 2

The FIRST and MOST CRITICAL step in histotechnology

Answer 2

FIXATION

Question 3

PRIMARY or SECONDARY AIM: to preserve the morphologic and chemical integrity of the cell in as life-like a manner as possible

Answer 3

PRIMARY

Question 4

PRIMARY or SECONDARY AIM: to harden and protect the tissue from the trauma of further handling

Answer 4

SECONDARY

Question 5

PRIMARY or SECONDARY AIM: for easy cutting during gross examination

Answer 5

SECONDARY

Question 6

the MOST IMPORTANT REACTION in fixation

Answer 6

STABILIZATION OF PROTEINS

Question 7

leaving a tissue specimen in air can cause it to __________

Answer 7

DRY OUT

Question 8

leaving the tissue in water (hypotonic soln) will cause the cell to _____________

Answer 8

SWELL

Question 9

leaving the tissue in strong salt (hypertonic soln) will cause the cell to __________

Answer 9

SHRINK

Question 10

The chemical constituent of the fixative is TAKEN IN and becomes part of the tissue through cross-links formation or molecular complexes

Answer 10

ADDITIVE

Question 11

examples of ADDITIVE FIXATIVES

Answer 11

1. FORMALDEHYDE
2. OSMIUM TETROXIDE
3. MERCURIC CHLORIDE

“naay FOMo si Bea kay Carlo”

Question 12

The fixing agent is NOT INCORPORATED into the tissue but alters the tissue composition and stabilizes it through water removal

Answer 12

NON-ADDITIVE

Question 13

pH for fixation

Answer 13

6.0 - 8.0 (ave: 7.0)

Question 14

TRADITIONAL/USUAL TEMP FOR FIXATION

Answer 14

ROOM TEMP (18-30°C)

Question 15

TISSUE PROCESSORS TEMP

Answer 15

40-42°C

Question 16

ELECTRON MICROSCOPY and HISTOCHEMISTRY temp

Answer 16

0-4°C

Question 17

used to slow down decomposition if the tissue needs to be photographed and cannot be fixed immediately

Answer 17

REFRIGERATION

Question 18

for rapid fixation of VERY URGENT BIOPSY SPECIMENS, formalin is heated to what temperature?

Answer 18

60°C

Question 19

to fix tissues with TUBERCULOSIS, formalin is heated to what temperature?

Answer 19

100°C

Question 20

BEST results are obtained using __________ solutions

Answer 20

SLIGHTLY HYPERTONIC

Question 21

added to OSMIUM TETROXIDE fixatives for EM

Answer 21

SUCROSE

Question 22

rate of fixative penetration

Answer 22

1mm/hr

Question 23

volume/amount of fixative

Answer 23

20x

Question 24

OSMIUM TETROXIDE fixative volume

Answer 24

5-10x

Question 25

IDEAL SIZE OF TISSUE TO BE FIXED

Answer 25

NOT MORE THAN 4mm

Question 26

PHYSICAL METHODS OF FIXATION

Answer 26

"CHM" (Cryopreservation, Heating, Microwaving)

Question 27

CHEMICAL METHODS OF FIXATION

Answer 27

"VIP" (Vapor Form, Immersion, Perfusion)

Question 28

MAJOR GROUP OF CHEMICAL FIXATIVES: act by creating COVALENT CHEMICAL BONDS between proteins in tissue

Answer 28

CROSSLINKING FIXATIVES

Question 29

MAJOR GROUP OF CHEMICAL FIXATIVES: act by REDUCING THE SOLUBILITY OF PROTEIN MOLECULES and (often) by DISRUPTING THE HYDROPHOBIC INTERACTIONS that give many proteins their tertiary structure

Answer 29

PRECIPITATING/DENATURING FIXATIVES

Question 30

removes lipids, dehydrate cells, and precipitate proteins

Answer 30

ORGANIC SOLVENTS

Question 31

form intermolecular bridges creating a network of linked antigens

Answer 31

CROSS-LINKING REAGENTS

Question 32

Fixatives that are made up of ONLY ONE COMPONENT SUBSTANCE

Answer 32

SIMPLE FIXATIVES

Question 33

Fixatives made up of TWO OR MORE FIXATIVES

Answer 33

COMPOUND FIXATIVES

Question 34

SIMPLE FIXATIVES: "AMPAAAO H!"

Answer 34

1. Aldehydes 2. Metallic Fixatives 3. Picric Acid 4. Acetic Acid 5. Acetone 6. Alcohol 7. Osmium Tetroxide 8. Heat

Question 35

fixatives that permit the **GENERAL MICROSCOPIC STUDY** of tissue structures

Answer 35

MICROANATOMICAL FIXATIVES

Question 36

MICROANATOMICAL FIXATIVES: "10-10 H-F Z-Z B-B"

Answer 36

1. 10% Formol Saline 2. 10% NBF 3. Heidenhain's Susa 4. Formol Sublimate 5. Zenker's Solution 6. Zenker-Formol 7. Bouin's Solution 8. Brasil's Solution

Question 37

Fixatives that PRESERVE SPECIFIC PARTS and PARTICULAR MICROSCOPIC ELEMENTS of the cell

Answer 37

CYTOLOGICAL FIXATIVES

Question 38

fixatives that preserve NUCLEAR STRUCTURE

Answer 38

NUCLEAR FIXATIVES

Question 39

pH of nuclear fixatives

Answer 39

≤ 4.6

Question 40

fixatives that preserve CYTOPLASMIC STRUCTURES

Answer 40

CYTOPLASMIC FIXATIVES

Question 41

pH of CYTOPLASMIC FIXATIVES

Answer 41

≥ 4.6

Question 42

fixatives that preserve the CHEMICAL CONSTITUENTS of cells and tissues

Answer 42

HISTOCHEMICAL FIXATIVES

Question 43

NUCLEAR FIXATIVES: "BFNCH"

Answer 43

1. Bouin's Fluid 2. Flemming's Fluid 3. Newcomer's Fluid 4. Carnoy's Fluid 5. Heidenhain's Susa

Question 44

CYTOPLASMIC FIXATIVES: "HORFF"

Answer 44

1. Helly's Fluid 2. Orth's Fluid 3. Regaud's Fluid 4. Flemming's Fluid w/out HAc 5. Formalin WITH post-chroming

Question 45

HISTOCHEMICAL FIXATIVES: "10F-ANA"

Answer 45

1. 10% Formol Saline 2. Absolute Ethyl Alcohol 3. Newcomer's Fluid 4. Acetone

Question 46

What organs should be packed with COTTON SOAKED IN FIXATIVE or completely opened before being immersed in adequate fixing solution?

Answer 46

HOLLOW ORGANS

Question 47

Air-filled lungs or HEALTHY LUNGS will _____

Answer 47

FLOAT

Question 48

Diseased lungs will ______

Answer 48

SINK

Question 49

What should be injected to EYES before immersing it in fixative?

Answer 49

FORMOL ALCOHOL

Question 50

failure to arrest early cellular autolysis is due to _____________

Answer 50

FAILTURE TO FIX IMMEDIATELY

Question 51

too little and too hard blocks is due to ________

Answer 51

PROLONGED FIXATION

Question 52

soft and feather-like tissues is due to

Answer 52

INCOMPLETE FIXATION

Question 53

1. removal of fixative soluble substances 2. enzyme inactivation and loss ARE DUE TO

Answer 53

WRONG CHOICE OF FIXATIVE

Question 54

presence of artefact pigments on sections are due to

Answer 54

INCOMPLETE WASHING OF FIXATIVE

Question 55

shrinkage and swelling of cells and tissue structures are due to

Answer 55

OVERFIXATION