Bor Microtomy

Front 1

Which of the following can be used to soften the exposed face of paraffin-embedded tissue that is too hard to section, such as uterine tissue?

a) acid
b) glycerine
c) heat
d) xylene

Back 1

b) glycerine

Front 2

The supplier sent paraffin with a melting point of 50°C to 52°C by mistake. When compared to paraffin with a melting point of 55°C, this paraffin weill:

Back 2

ribbon more easily

yield thicker sections

provide better support for small/soft tissues

require a cooler water bath

Front 3

A different kind of paraffin is under consideration for use in the laboratory. An important fact to remember is that as the melting point of paraffin is increased, the paraffin:

Back 3

becomes harder

ribbons more difficultly

yields thinner sections

Front 4

To obtain a small bowel showing mucosa, sub-mucosa, muscularis externa, and adventitia, the tissue must be embedded:

Back 4

on edge

Front 5

Holes are noted in a frozen section of skeletal muscle. This is most likely the result of:

Back 5

freezing the specimen too slowly

Front 6

The angle formed between the block face and the cutting facet of a knife is known as the:

Back 6

clearance angle

Front 7

Which of the following will most likely be corrected by soaking a faced block in ice water?

a) lengthwise splits in the sections
b) compressed and jammed sections
c) microscopic chatter
d) mushy sections

Back 7

c) microscopic chatter

Front 8

Which of the following artifacts may be introduced during the flotation process?

a) holes in the tissue
b) the "venetian blind" effect
c) lengthwise splits in the ribbon
d) separation of tissue elements

Back 8

d) separation of tissue elements

Front 9

Which of the following embedding procedures involves first infiltrating the tissue with one medium and then embedding it in another?

a) double
b) resin
c) routine
d) vacuum

Back 9

a) double

Front 10

A section of liver is cut in the cryostat and the sections obtained are alternately thick and thin, with a distinct "venetian blind" effect. The most probably cause of this artifact is that the:

Back 10

knife is dull

Front 11

The type of microtome used for routine paraffin sectioning is a:

Back 11

rotary microtome

Front 12

When frozen sections stick to a cryostat anti-roll plate, the plate is:

Back 12

too warm

Front 13

Knives used for sectioning paraffin blocks should be cleaned with:

Back 13

xylene and alcohol

Front 14

To remove grit and dirt before embedding, paraffin may have to be:

Back 14

filtered

Front 15

Microorganism contaminants on slides are usually picked up from:

Back 15

the flotation bath

Front 16

When a frozen tissue block rubs the anti-roll plate, the plate is:

Back 16

too far above the knife plate

Front 17

Microscopic examination of an H&E-stained section reveals the presence of irregular holes scattered throughout the section. This is most likely caused by:

Back 17

sections being taken immediately after "rough facing" of the block

Front 18

It is important that the facet of a cryostat knife be small to prevent:

Back 18

problems with the anti-roll plate

Front 19

Multiple skin sections should be embedded with the epithelial surfaces facing in:

Back 19

the same direction

Front 20

Microscopic examination of an H&E-stained section reveals marked background staining. This is most likely caused by:

Back 20

excess section adhesive on the slide

Front 21

Sections of paraffin-embedded tissue show straight lines that appear to be fissures of cuts running at many different angles. This artifact is most likely due to:

Back 21

use of quick-freeze spray to chill the block

Front 22

Hard or bony tissue should be embedded:

Back 22

at an angle

Front 23

Tubular tissue structures should be embedded:

Back 23

on end

Front 24

To protect the exposed tissue during storage, paraffin blocks may need to be:

Back 24

dipped

Front 25

The edge of a newly-sharpened microtome knife should be checked with a:

Back 25

dissecting microscope

Front 26

A microtome is the most likely cause of poor sections when the microtome is:

Back 26

old or has worn surfaces

Front 27

When frozen sections appear above the anti-roll plate of a cryostat, the plate is:

Back 27

too far below the knife edge

Front 28

Biopsies of which of the following tissue should be sections at 2micrometers?

a) bladder
b) heart
c) kidney
d) liver

Back 28

c) kidney

Front 29

Which of the following will cause a split or lengthwise scratch in a paraffin ribbon?

a) debris on the knife edge
b) inadequate processing
c) a knife edge that is too sharp
d) using embedding paraffin with the wrong melting point

Back 29

a) debris on the knife edge

Front 30

The purpose of embedding tissue in paraffin is to:

Back 30

provide support

Front 31

Which of the following groups of special stains requires sections to be cut at 8 to 10 micrometers?

a) Congo red, Lieb crystal violet, Bielchowsky
b) Kinyoun, Snook, Oil red O
c) von Kossa, Fontana-Masson, Sudan black B
d) Verhoeff-van Gieson, aldehyde fuchsin, Masson trichrome

Back 31

a) Congo red, Lieb crystal violet, Bielchowsky

Front 32

During sectioning of a block of uterine tissue, alternate thick and thin zones are observed. This is most likely caused by:

Back 32

vibration of the knife

Front 33

Microscopic examination of an H&E-stained section reveals the presence of extraneous epithelial cells. This is most likely caused by:

Back 33

albumin spread on the slide by the finger

Front 34

Disposable knife blades should be discarded:

Back 34

in a "sharps" box

Front 35

When tissue varies in hardness within a sample, such as skin or bone, the block should be positioned in the microtome so that the:

Back 35

knife passes through the hardest portion last

Front 36

Of the following tissues, which should be sectioned at 3 micrometers?

a) brain
b) breast
c) liver
d) lymph node

Back 36

d) lymph node

Front 37

When frozen sections split vertically as they are cut, the anti-roll plate is:

Back 37

defective on the edge

Front 38

Which of the following knife profiles is recommended for the majority of paraffin microtomy?

a) biconcave
b) planoconcave
c) tool edge
d) wedge

Back 38

d) wedge

Front 39

The orientation of a specimen for embedding should be decided during:

Back 39

grossing

Front 40

When cutting 30um sections of fixed brain tissue in a -15°C cryostat, the sections fragment at the knife edge. This problem could most likely be prevented by:

Back 40

raising the cryostat temperature to -5°C

Front 41

Unfixed cryostat sections are most commonly attached to slides by:

Back 41

picking them up from the knife onto a clean, warm slide

Front 42

When paraffin with a 54°C to 56°C melting point is used for embedding, the temperature of the flotation bath should fall within which of the following temperature ranges?

a) 41°C to 45°C
b) 46°C to 50°C
c) 51°C to 55°C
d) 56°C to 60°C

Back 42

b) 46°C to 50°C

Front 43

Routine cryostat sections are usually cut at:

Back 43

-20°C

Front 44

Lubricants used during knife sharpening are usually composed of:

Back 44

oil

Front 45

Sections are being lifted from the knife on the upstroke. This is probably because the:

Back 45

knife tilt is incorrect

Front 46

Which of the following groups of abrasive compounds is used for micrtome knife sharpening?

a) carborundum, diamon, zinc oxide
b) diamond, zinc oxide, jewler's rouge
c) lead acetate, zinc oxide, jeweler's rouge
d) carborundum, diamond, jeweler's rouge

Back 46

d) carborundum, diamond, jeweler's rouge

Front 47

Cryostat sections of fixed tissue are tending to float off the slides during staining. This problem can be prevented in the future by:

Back 47

coating the slides with an adhesive mixture

Front 48

The proper speed for cutting frozen sections:

Back 48

is similar to that used for paraffin sections

Front 49

The block is faced and sections are cut and mounted on a slide. More of the block is trimmed away and more sections are cut and mounted on a slide. The sections produced by this technique are known as:

Back 49

levels

Front 50

To prevent the formation of a thick layer of paraffin on the bottom of the mold during embedding, the tissue must be:

Back 50

embedded quickly and neatly

Front 51

The tissue surface to be cut should be placed against which aspect of the embedding mold?

Back 51

bottom

Front 52

Paraffin is converted from the fluid state to the solid state by:

Back 52

crystallization

Front 53

Routine paraffin sections are cut at what micrometer setting?

Back 53

4-5

Front 54

As the block face is trimmed, the knife digs into the tissue and gouges out a chunk. The most probably cause of this problem is that the:

Back 54

the block is loose in the chuck

Front 55

Nuclear bubbling is seen on an H&E section. This most likely was caused by:

Back 55

drying undrained slides at too high a temperature

Front 56

The clearance angle used with most microtome knives is:

Back 56

3 to 8 degrees

Front 57

Microscopic examination of an H&E-stained section reveals the presence of extraneous tumor cells. This is most likely caused by:

Back 57

the flotation bath not being cleaned between blocks

Front 58

Layered structures such as cyst wall and gallbladder should be embedded:

Back 58

on edge

Front 59

During paraffin embedding, it is noted that several sections appear soft and mushy. This is most likely due to:

Back 59

inadequate processing

Front 60

Which of the following is necessary to ensure a straight ribbon?

a) horizontal sides of the block must be parallel
b) vertical sides of the block must be parallel
c) horizontal and vertical sides of the block must be parallel
d) the microtome wheel must be rotated rapidly

Back 60

a) the horizontal sides of the block must be parallel

Front 61

Microscopic examination of stained slides shows bacilli on, but not in, the tissue sections. The most probably cause of this contaminant is that:

Back 61

the water bath was not cleaned after previous use

Front 62

Paraffin used for embedding should be how many degrees centigrade above the melting point of the medium?

Back 62

2 to 4

Front 63

Sections of brain that tend to wash off slides during staining can be adhered to the slides by coating the section/slide with:

Back 63

poly-L-lysine

Front 64

Frozen sections are required when:

Back 64

immediate microscopic evaluation is required

Front 65

When frozen sections partially jam and partially slide under the anti-roll plate, the plate is:

Back 65

not parallel to the knife edge

Front 66

One cause of sections sticking to each other or to parts of the microtome is:

Back 66

static electricity

Front 67

Microtome knives used for paraffin sectioning are usually made of:

Back 67

carbon steel

Front 68

Which of the following groups of plates may be used to support abrasive powders and lubricants for sharpening knives?

a) copper, glass, and iron
b) aluminum, copper, and glass
c) copper, iron, and glass
d) glass, aluminum, and iron

Back 68

a) copper, glass, and iron

Front 69

Which of the following problems will be seen in paraffin sections that are floated out on a flotation bath that is too cold?

a) cracks
b) folds
c) separations
d) stretching

Back 69

b) folds

Front 70

During microtomy, several successive paraffin sections are compressed and wrinkled. The most appropriate action is to:

Back 70

change to a new blade

Front 71

Cryostate Temperature Chart:

Monday -20°C
Tuesday -15°C
Wednesday -18°C
Thursday -23°C
Friday -26°C

On which day would sectioning of breast tissue be most difficult?

Back 71

Tuesday

Front 72

Which of the follwing could be substituted for gelatin as an additive to the flotation bath?

a) aminoalkylsaline
b) chromium potassium sulfate
c) poly-L-lysine
d) agar

Back 72

d) agar

Front 73

During microtomy, it is noted that a faced block that has been soaking in ice water contains a bulging white area. This is most likely the result of:

Back 73

inadequate dehydration

Front 74

Lymph node tissue shatters when sectioned in a cryostat maintained at -20°C. The most appropriate action is to:

Back 74

warm the block slightly

Front 75

For good demonstration of myelin sheaths, paraffin sections should be:

Back 75

cut 10um to 15um thick

Front 76

In paraffin microtomy, knowledge of the possible disease process present in the tissue may be important because it may change the requirements in:

Back 76

section thickness (different stains need different thickness)

Front 77

Prominent peripheral chatter is obtained on sections of a paraffin block that has been routinely fixed and processed. This can probably be corrected by recutting the block:

Back 77

after soaking it in ice water

Front 78

Slides used for mounting open-top cryostat frozen sections should be kept at the same temperature as the:

Back 78

room

Front 79

Paraffin sections should be cut at 2um when studying:

a) basement membranes
b) amyloid
c) myelin
d) nerve fibers

Back 79

a) basement membranes

Front 80

The tissue block fails to advance during preparation of frozen sections. This probably could be corrected by:

Back 80

cleaning and oiling the microtome

Front 81

An H&E-stained lymph node section reveals oberlapping nuclei. This indicates that the section is most likely:

Back 81

too thick

Front 82

The material of choice for immunofluorescence microscopy and enzyme histochemical studies is:

Back 82

cryostat sections

Front 83

When a femoral head is sectioned, the marrow portion sections satisfactorily but the cortex fragments. The most probably cause of this problem is that the:

Back 83

compact bone is underdecalcified

Front 84

A fingernail has been fixed in formalin, routinely processed, and embedded in paraffin. The tissue is very hard and sections are difficult to obtain. Sectioning quality will be improved and tissue components will be best preserved and demonstrated by gently facing the block and:

Back 84

soaking in a solution that softens keratin