ADHESIVES, MOUNTING MEDIA AND MICROTOMY

Question 1

COMMON TYPES OF ADHESIVES

Answer 1

MAYER’S EGG ALBUMIN
DRIED ALBUMIN
GELATIN
GELATIN-FORMALDEHYDE MIXTURE
STARCH PASTE
PLASMA
POLY-L-LYSINE
APES (3-AMINOPROPYLTHRIETHOXYSILANE)

Question 2

dried albumin components

Answer 2

5 grams albumin, 5 g NaCl, 100cc distllled water

Question 3

gelatin (1%) components

Answer 3

1 gm gelatin, 100m water, 15ml glycerol, 2 gm penol crystals

Question 4

Gelatin-formaldehyde mixture

Answer 4

1% gelatin 5ml, 2% formaldehyde 5ml

Question 5

starch paste composition

Answer 5

1 g powdered starch, 30ml water, 2 drops HCl and thymol crystals.

Question 6

plasma adhesive composition

Answer 6

Plasma is readily available from outdated blood stored in blood banks, dispensed into sterile tubes of 0.5ml each.

Question 7

can be purchased as a 0.1% solution which is further diluted at 1:10 with distilled water (final dilution to 0.01%) prior to use. Sections are coated with this solution and allowed to dry.

Answer 7

Poly-L-Lysine

Question 8

widely used as a section adhesive in immunohistochemistry.

Answer 8

Poly-L-Lysine

Question 9

for cytospin preparations of proteinaceous or bloody material.

Answer 9

APES (3-Aminopropylthriethoxysilane)

Question 10

Is usually syrupy fluid applied between the section and the coverslip after staining, setting the section firmly, preventing the movement of the coverslip.

Answer 10

mounting medium

Question 11

CHARACTERISTICS OF GOOD MOUNTING MEDIUM

Answer 11

Avoid tissue distortion
Miscible with xylene and toluene
Should not dry quickly
Should not crack or produce artefactual granularity on the slide upon drying
Should not dissolve out or fade tissue sections
Should not cause shrinkage and tissue distortions
Should not leach out any stain or affect staining
Should not change color or pH
Should set hard, producing permanent mounting of sections

Question 12

mounting medium 2 main groups

Answer 12

1. aqueous media
2. resinous mounting media

Question 13

Are designed to mount water-miscible preparations directly from water in cases where the stain is removed or decolorized with alcohol or xylene

Answer 13

aqueous media

Question 14

example of aqueous media

Answer 14

water, glycerin

Question 15

Has low refractive index, moderately transparent and evaporates easily

Answer 15

water

Question 16

Has high refractive index, provides greater visibility if slightly diluted with water.

Answer 16

Glycerin

Question 17

Glycerin media example

Answer 17

Glycerin Jelly
Farrant’s Medium
Apathy’s Medium
Brun’s Fluid

Question 18

Are used for preparations that have been dehydrated and cleared in xylene or toluene.

Answer 18

Resinous Mounting Media

Question 19

Transparent, almost colorless oleoresin that adheres firmly to glass and sets to a hard consistency without granulation

Answer 19

Canada Balsam

Question 20

canada balsam is dissolved in xylene in an incubator at ____ or paraffin oven at ___

Answer 20

37 deg.c ; 58 deg celsius

Question 21

Resinous medium, for small tissue sections

Answer 21

DPX - dibutyl phtalate and xylene (Refractive Index 1.532)

Question 22

refractive index 1.52
Synthetic resin mixture in xylene

Answer 22

XAM

Question 23

refractive index 1.544
synthetic resin soluble in xylene
preferred than DPX

Answer 23

clarite

Question 24

Is the process of sealing the margins of the cover slip to prevent the escape of fluid or semi-fluid mounts and evaporation of mountant
immobilized the coverslip
Prevent sticking of the slides upon storage

Answer 24

ringing

Question 25

For cutting serial sections of large blocks of paraffin embedded tissues

Answer 25

rocking microtome

Question 26

For cutting sections for electron microscopy

Answer 26

ultrathin microtome

Question 27

For cutting paraffin embedded sections

Answer 27

rotary microtome

Question 28

For cutting celloidin embedded sections

Answer 28

sliding microtome

Question 29

For cutting umembedded frozen sections

Answer 29

freezing microtome

Question 30

for manual sharpening when cutting edge has been rendered blunt or nicked

Answer 30

belgium yellow

Question 31

gives more polishing effect than the belgium yellow

Answer 31

arkansas

Question 32

much coarser than the first two types and is used only for badly nicked knives followed by either one of the first two knife sharpeners

Answer 32

fine carborundum

Question 33

hone is about ____ long; remove ____

Answer 33

8"x3" long; remove irregularities

Question 34

Its surface is wiped clean with a soft moistened with xylene in order to remove the scattered small particles of stones and metal. Then, covered with a thin film of mineral and clove oil, xylene, liquid paraffin or soapy water for lubrication

Answer 34

hone

Question 35

direction of hone

Answer 35

Heel (handle end) to toe (head portion) direction

Question 36

hone knife

Answer 36

10-20x minot/plane wedge knife

Question 37

Used vibrating frosted glass plate or wheel driven by an electrical motor Approximately 30 double strokes are given each side of the knife to which very gently pressure is applied Quite expensive Time saving Produced well sharpened knives with uniform levels

Answer 37

MECHANICAL MICROTOME KNIFE SHARPENING

Question 38

precaution for mechanical microtome knife sharpening

Answer 38

lubricated with warm soapy water or fine oil before using, then washed with water Presure should be gentle Strokes should be 20-30x in each direction After honing wipe off the oil or soap from the knife with xylene Then strop it thoroughly

Question 39

BURR formed during honing is removed To polish and sharpen the cutting edge Toe to heel direction Paddle strop made up of best quality horse leather 40-120 double strokes

Answer 39

Stropping (polishing)

Question 40

PRECAUTIONS IN STROPPING

Answer 40

Knife should be wiped clean with cloth Knife edge is oiled or greased to prevent rusting Strop should be treated with vegetable oil (castor oil) applied at the back of the strop not the surface; it should not be used for at least 24-48 hrs after treatment Mineral oil is NOT recommended

Question 41

2 types of disposable blades

Answer 41

glass knives diamond knives

Question 42

used fro trimming and semi-thin sectioning of tissue blocks for EM

Answer 42

glass knives

Question 43

cut any type of resin block for electron microscopy

Answer 43

diamond knives

Question 44

a disposable blades that is Brittle and expensive Very durable

Answer 44

diamond knives