Infiltration & Embedding, Sectioning, Staining, Mounting & Labelling

Question 1

In reusing wax, water must be removed by heating the wax to ___C thereby raising its melting point.

Answer 1

100-105

Question 2

In double embedding, tissue is first infiltrated with ____, followed by embedding with ____.

Answer 2

Celloidin; paraffin

Question 3

Most rapid embedding technique

Answer 3

Vacuum

Question 4

What is the temperature of the paraffin oven used for impregnation?

Answer 4

2-5C above the melting point of impregnating medium

Question 5

Sections are floated out in a water bath set at:

Answer 5

45-55C

Question 6

What is the melting point of ester wax?

Answer 6

46-48C

Question 7

Most common type of microtome for cutting paraffin embedded sections

Answer 7

Rotary microtome, Minot

Question 8

The knife is usually tilted at ___ angulation on a microtome to allow a clearance angle between the cutting facet and the tissue block.

Answer 8

0-15C

Question 9

Volume of the embedding medium should be at least ___ times the tissue volume.

Answer 9

25

Question 10

In manual processing, there should be at least ___ changes of paraffin at ___ minutes interval.

Answer 10

4; 15

Question 11

Automatic tissue processing comprise of ___ individual processing steps.

Answer 11

12

Question 12

Medium used when dehydration is to be avoided; used for tissues subjected to histochemical and enzyme studies

Answer 12

Gelatin

Question 13

Plastic medium used for electron microscopy

Answer 13

Methacrylate plastic resin (EPON resin)

Question 14

Plastic medium used extensively for light microscopy

Answer 14

Acrylic

Question 15

Overheated paraffin (>60) causes ____ of tissue.

Answer 15

Brittleness, shrinkage, and hardening

Question 16

What is the melting point of paraplast?

Answer 16

56-57C

Question 17

Mixture of highly purified paraffin and synthetic plastic polymers

Answer 17

Paraplast

Question 18

Synthetic wax recommended for eyes

Answer 18

Bioloid

Question 19

TRUE or FALSE: Carbowax requires dehydration and clearing.

Answer 19

False

Question 20

Adding soap to water or using ____ will reduce tissue distortion when employing carbowax.

Answer 20

10% polyethylene glycol

Question 21

Celloidin method recommended for bones, teeth, large brain sections and whole organs

Answer 21

Wet celloidin method

Question 22

In dry celloidin method, ____ is added to celloidin blocks before hardening.

Answer 22

Gilson’s mixture

Question 23

Embedding mold consisting of 2 L-shaped pieces of metal

Answer 23

Leuckhart’s

Question 24

Embedding mold that allows the block to be immediately ready for cutting without the need for trimming

Answer 24

Plastic embedding ring and base mold

Question 25

At least ___ mm of wax should surround the tissue block.

Answer 25

2

Question 26

Tissue is soft when block is trimmed - incomplete ____

Answer 26

Fixation

Question 27

Clearing agent turn milky - incomplete ____

Answer 27

Dehydration

Question 28

Air holes found on tissue during trimming - incomplete ____

Answer 28

Impregnation

Question 29

Simplest type of microtome

Answer 29

Rocking (Paldwell Trefall)

Question 30

Most dangerous type of microtome; for cutting celloidin-embedded tissues

Answer 30

Sliding (Adams)

Question 31

Which sliding microtome is used for hard tissue or large blocks?

Answer 31

Base sledge

Question 32

TRUE or FALSE: In the standard sliding microtome the block holder is stationary and the knife is moving.

Answer 32

True

Question 33

TRUE or FALSE: The knife is colder than the tissue and environment in the freezing microtome.

Answer 33

True

Question 34

What is the temperature of the knife in the freezing microtome?

Answer 34

-40 to -60C

Question 35

Most commonly used for rapid preparation of urgent tissue biopsies during surgery

Answer 35

Cryostat or cold microtome

Question 36

What is the optimum working temp of the cryostat?

Answer 36

-18 to -20C

Question 37

Most rapid freezing agent; produce ice crystals

Answer 37

Liquid nitrogen

Question 38

Most commonly used in cold knife procedure

Answer 38

Carbon dioxide gas

Question 39

In freeze-drying, quenching is set at what temperature?

Answer 39

-160 to -180C

Question 40

In freeze-substitution, the frozen tissue is fixed in ____ or in ____ and dehydrated in absolute alcohol.

Answer 40

Rossman's fluid; 1% acetone

Question 41

What is the recommended knife for cutting paraffin-embedded sections on a rotary microtome?

Answer 41

Biconcave knife

Question 42

What is the recommended knife for frozen sections or cutting large and tough specimens, using base-sledge type or sliding microtome?

Answer 42

Plane-wedge knife

Question 43

TRUE or FALSE: The less concave side of the plane-concave knife is for paraffin-embedded tissue blocks.

Answer 43

False

Question 44

Removal of gross nicks and blemishes on the knife

Answer 44

Honing (sharpening)

Question 45

Removal of burr; polishing of the cutting edge of the knife

Answer 45

Stropping

Question 46

Angle formed between the cutting edges of the knife

Answer 46

Bevel angle (27-32)

Question 47

Angle between the cutting edge and the tissue block

Answer 47

Clearance angle (0-15)

Question 48

Perfect and optimum cutting angle

Answer 48

15

Question 49

Paraffin sections are ____ micra.

Answer 49

4-6

Question 50

What is the maximum volume of a flotation bath?

Answer 50

2L

Question 51

What is the optimum temperature of a water bath?

Answer 51

6-10C lower than the melting point of waxed used (45-50)

Question 52

Most common adhesive for surgical sections

Answer 52

Mayer's egg albumin

Question 53

What are added to Mayer's egg albumin to prevent growth of molds?

Answer 53

Thymol crystals

Question 54

What is added to Mayer's egg albumin to increase viscosity and prevent drying?

Answer 54

Glycerin

Question 55

What adhesive is used for cytospin preparations of proteinaceous or bloody material?

Answer 55

APES (3-aminopropyltriethoxysilane)

Question 56

Wax oven should be 55-60C or at least ____C above the melting point of wax.

Answer 56

2-5

Question 57

A process whereby the action of the dye is intensified by adding another agent of mordant

Answer 57

Indirect staining

Question 58

A commonly used connective tissue procedure that stains collagen

Answer 58

Masson trichrome

Question 59

Stains DNA and RNA

Answer 59

Acridine orange

Question 60

Dyes used for nuclear staining are:

Answer 60

Basic

Question 61

The silver nitrate reduction technique of Fontana may be used to demostrate:

Answer 61

Argentaffin cells

Question 62

Special stain for the demonstration of fungus and Pneumocystis carinii organisms in lung tissue sections:

Answer 62

Grocott's methanamine silver

Question 63

Using the warthin-starry method for the demonstration of spirochetes, the organism is positively stained as:

Answer 63

Black

Question 64

Best vital dye

Answer 64

Neutral red

Question 65

Vital stain recommended for mitochondria

Answer 65

Janus green

Question 66

A vegetable dye extracted from lichens

Answer 66

Orcein

Question 67

Acid alcohol used in routine H & E staining acts as:

Answer 67

Differentiator

Question 68

Oldest of stains; stains amyloid, cellulose, carotenes & glycogen

Answer 68

Iodine

Question 69

Excellent stain for elastic fibers and is especially recommended in dermatological studies due to its ability to demonstrate the finest and most delicate fibers in the skin

Answer 69

Orcein

Question 70

In the methyl green-pyronin stain, DNA is stained:

Answer 70

Green or blue-green

Question 71

Type of staining wherein the action of the dye is intensified by adding another agent or mordant

Answer 71

Indirect staining

Question 72

Accelerates the speed of staining reaction by increasing staining power & selectivity

Answer 72

Accentuator