SECTION-CUTTING, HONING AND STROPPING

Question 1

Three Basic Types or Shapes

Answer 1

1. Plane-Concave Knife
2. Biconcave Knife
3. Plane-Wedge Knife

Question 2

Trimming and section-cutting are done w/ a

Answer 2

microtome knife

Question 3

(25 mm in length)

Answer 3

Plane-Concave Knife

Question 4

-One side of the knife is flat while other is concave.

Answer 4

Plane-Concave Knife

Question 5

-Less concave sides are recommended for cutting Celloidin-embedded tissue blocks on a sliding microtome
microtome
-More concave sides used to cut paraffin sections on base-sledge, rotary or rocking Microtome

Answer 5

Plane-Concave Knife

Question 6

(usually 120 mm in length)

Answer 6

Biconcave Knife

Question 7

-w/ both sides concave

Answer 7

Biconcave Knife

Question 8

-recommended for cutting paraffin-embedded sections on a rotary microtome

Answer 8

Biconcave Knife

Question 9

(usually 100 mm in length)

Answer 9

Plane-Wedge Knife

Question 10

-both sides straight

Answer 10

Plane-Wedge Knife

Question 11

• recommended for frozen sections or cutting extremely hard and tough specimens embedded in paraffin blocks
• using a base-sledge type or sliding microtome

Answer 11

Plane-Wedge Knife

Question 12

-it is the angle formed between cutting edges. It usually 27o to 32o

Answer 12

“Bevel Angle”

Question 13

the angle formed between cutting edges of a bevel angle

Answer 13

27o to 32o

Question 14

-a good cutting edge should be made of good quality steel. Too soft cutting edges are likely to become dull easily, while too hard edges are likely to produce nicks or jagged edges and irregularities, thereby producing tears or striation on the tissue sections during cutting.

Answer 14

“Bevel Angle”

Question 15

-a good cutting edge must be able to cut good sections from a paraffin wax block about 2-3 microns thick, without any serration noted on examination.

Answer 15

“Bevel Angle”

Question 16

Theoretically, the perfect and optimum cutting angle is obtained when the sides of the wedge knife are inclined at an angle of about 15 degrees, causing maximum penetration of the tissues and minimizing distortion, causing maximum penetration of the tissues and minimizing distortion.

Answer 16

Clearing angle

Question 17

-process where badly nicked knives w/ blunted ends, jagged edges must undergo sharpening in order to prevent gross irregularities and tearing of tissue sections.

Answer 17

Honing and Stropping

Question 18

Sharpening of knife involves two stages:

Answer 18

1. Honing

2. Stropping

Question 19

-removal of gross nicks on the knife (coarse honing) to remove blemishes and grinding the cutting edge of the knife on a stone

Answer 19

Honing

Question 20

a natural sharpening stone or hard grinding surface (carborundum) serves to remove nicks and irregularities of the knife edges

Answer 20

Hone

Question 21

Types of Hones:

Answer 21

1. Belgium Yellow
2. Arkansas
3. Fine carborundum

Question 22

much coarser than the first two, used only for badly nicked knives followed by either the two

Answer 22

Fine carborundum

Question 23

gives more polishing effect than Belgium Yellow

Answer 23

Arkansas

Question 24

for manual sharpening when cutting edge has been rendered blunt or nicked. This type give the
best result

Answer 24

Belgium Yellow

Question 25

Lubrication:

Answer 25

a. Mineral
b. Clove oil
c. Xylene
d. Liquid paraffin or soapy water

Question 26

• Edge First, w/ a Heel to Toe direction

Answer 26

Honing

Question 27

-Process whereby the “burr” formed during honing is removed and the cutting edge of the knife is polished.

Answer 27

Stropping

Question 28

Edge last, Toe To Heel direction

Answer 28

Stropping

Question 29

can cut 2-4 micra thick section

Answer 29

Disposable Blades

Question 30

-suitable for use in the cryostat

Answer 30

Magnetic knives

Question 31

-used for trimming and semi-thin sectioning of tissue blocks for electron microscopy

Answer 31

Glass Knives

Question 32

are used to cut any type of resin block for electron microscopy-are used to cut any type of resin block for electron microscopy

Answer 32

Diamond Knives

Question 33

is a process whereby tissues are cut into uniformly thin slices or “sections”

Answer 33

“Sectioning”

Question 34

Three General Types of Tissue Sections

Answer 34

1. Paraffin Sections
2. Celloidin Sections
3. Frozen Sections

Question 35

w/c may be cut from tissues that have been fixed and frozen w/ CO2 or for fresh or fixed
tissues frozen w/ cryostat

Answer 35

Frozen Sections

Question 36

for celloidin embedded tissues w/c are usually cut by means of the sliding microtome for celloidin embedded tissues w/c are usually cut by means of the sliding microtome

Answer 36

Celloidin Sections

Question 37

paraffin embedded tissue blocks w/c may be cut by rocking and rotary microtome

Answer 37

Paraffin Sections