Sectioning Flashcards by PATRICIA ONG

a process whereby tissues are cut into
uniformly thin slices or sections with the aid of a
machine

SECTIONING

How well did you know this?

Not at all

Perfectly

tissue blocks cut using rocking & rotary
microtome.

Paraffin Section

How well did you know this?

Not at all

Perfectly

tissues which are usually cut using sliding
microtome

Celloidin Section

How well did you know this?

Not at all

Perfectly

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

Frozen Sections

How well did you know this?

Not at all

Perfectly

Size for Paraffin sections:

4-6 um

How well did you know this?

Not at all

Perfectly

Size for Celloidin sections:

10-15um

How well did you know this?

Not at all

Perfectly

Size for Frozen sections (cryostat):

4 um

How well did you know this?

Not at all

Perfectly

where the tissue block is
held in position; Part that holds a tissue block

Block holder/CHUCK

How well did you know this?

Not at all

Perfectly

used for actual tissue cutting;
(now: disposable blades); important parts

Knife carrier & knife

How well did you know this?

Not at all

Perfectly

part that we move mechanically to
start the cutting process

Rotating wheel

How well did you know this?

Not at all

Perfectly

used to line up the tissue block in proper position with the knife

Pawl, ratchet feedwheel & adjustment screw

How well did you know this?

Not at all

Perfectly

Invented by Trefall; most simple

Rocking Microtome

How well did you know this?

Not at all

Perfectly

Thickness of sections for Rocking Microtome

10-12 um

How well did you know this?

Not at all

Perfectly

Purpose of Rocking microtome

prepare serial section of large paraffin blocks

How well did you know this?

Not at all

Perfectly

DISADVANTAGE of Rocking Microtome

difficulty in re-orienting the block

restriction in the size of the block that
can be cut

How well did you know this?

Not at all

Perfectly

Most common microtome; Invented by Minot

Rotary microtome

How well did you know this?

Not at all

Perfectly

Size of sections Rotary Microtome

4-6 u

How well did you know this?

Not at all

Perfectly

Purpose of rotary microtome

used to cut paraffin embedded
tissues

How well did you know this?

Not at all

Perfectly

Invented by Adams; most dangerous – due to
exposed knife

Sliding Microtome

How well did you know this?

Not at all

Perfectly

Thickness of sections in Sliding microtome

7-9 u

How well did you know this?

Not at all

Perfectly

Purpose of sliding microtome

cut celloiding embedded

How well did you know this?

Not at all

Perfectly

Two types of sliding microtome

Base sledge and Standard sliding

How well did you know this?

Not at all

Perfectly

less dangerous because the
moveable type is the block holder and the one that
remains stationary is the knife.

Base Sledge

How well did you know this?

Not at all

Perfectly

more dangerous; the one that is
fixed is the black holder and the moveable part is the
knife.

Standard sliding

How well did you know this?

Not at all

Perfectly

Purpose of ultrathin microtome

cutting tissues of Electron Microscopy

Thickness of Sections in Ultrathin

0.5 u

Tissues are usually embedded in plastic type of mirotome

ultrathin microtome

usually prepared for rapid diagnosis (when patients are still in the OR)

Frozen sections

Uses rotary microtome

PARAFFIN SECTIONS

Sliding microtome are generally used for

celloidin sections

need a freezing microtome

Cold Knife Procedure

Invented by queckette

Freezing microtome

Uses intermittent burst of carbon dioxide to freeze the block holder and tissue, also With a second cooling device for lowering temperature of knife

Freezing microtome

Thickness of sections freezing microtome

10-15 um

Purpose of freezing microtome

demonstration of fats and other neurological structures used to cut tissues with heat sensitive structures.

uses freezing agent (Carbon dioxide [CO2] to immediately harden fresh tissues to facilitate immediate cutting)

Freezing microtome

refrigerated apparatus- a microtome that is enclosed in a cold chamber (rotary microtome)

Cryostat or Cold microtome

Cryostat or Cold: fresh tissue microtomy is refrigerated at

-5 to -30 °C average is: -20 °C

remove the wax that surrounds the tissue

DEPARAFFINIZATION

process of removing excess paraffin wax from tissues once properly fixed on the slide prior to staining

Deparaffinization

METHODS of DEPARAFFINIZATION

Passing the slide over a flame using alcohol lamp Immersion of slides in xylene Placing the slides inside the over (55-60 °C)

Microtome Knives: 25mm long one side of the knife is flat: celloidin section concave: cutting paraffin embedded tissues

Plane Concave

120mm long both sides are concave and used to cut paraffin embedded tissues

Biconcave

usually 100mm long both sides of the knife are flat; used to cut frozen sections, extremely hard or tough tissue

Plane Wedge

angle formed between the cutting edges; 27-32 degrees

Bevel angle

– angle formed between the surface of the block and the cutting edge of the knife;

Clearance angle/Tilt angle/Inclination angle

Clearance angle/Tilt angle/Inclination angle:

0-15 degrees

angle formed by the sides of the wedge knife; 14-15 degrees

Wedge angle

angle to prevent uneven sections/section that are alternately thin/thick

5-10 degrees

used for cutting today instead of microtome knives; 2-4 u

DISPOSABLE BLADES

semi-thin section for Electron Microscopy

GLASS KNIVES

utilized for electron microscopy

DIAMOND KNIVES

Blunt/Dull polish & sharpen the cutting edge & to remove BURRS and other irregularities formed during honing

STROPPING

removing gross nicks; grinding the cutting edge

HONING

HONES/OIL STONES: usually gives the best result

Belgium yellow

HONES/OIL STONES: has a more polishing effect than belgium yellow

Arkansas

HONES/OIL STONES: for badly nicked knives; with a much coarser bite

Fine Carborundum

Honing movement

HEEL to TOE MOVEMENT, edge first

number of strokes depends on the knicks of the knife); required number of strokes

20-30 strokes (minimum)

Lubricants of honing

Soapy water Mineral oil Clove oil Xylene or liquid paraffin

Purpose of Stropping

process of polishing and sharpening the cutting edge polish & sharpen the cutting edge remove BURRS and other irregularities formed during honing

Materials for stropping:

LEATHER STROP/ HORSE LEATHER

Procedure stropping

TOE to HEEL MOVEMENT; edge last

Requirement of STROKES required for stropping

40-120 double strokes (minimum) [you can do beyond 120 depending on the condition of the knives]

True or False: Stropping does not require lubricant

True

Treated with oil prior to use

Strops are usually

What blisters and destroys the leather

mineral oil

may be carried out without prior honing must be done after the process of honing

Stropping

will not require honing and stropping

Disposable blades

will require honing and stropping

Microtome knives

IN CASE HORSE LEATHER AND OIL STONES IS NOT AVAILABLE:

Glass Plates; abrasive, honing Diamantine; stropping

with finely powdered aluminum oxide made into paste with water; used as abrasive; HONING

Glass Plates

to be used for final polishing; STROPPING

Diamantine-

Thin slices of tissues

Ribbons

remove wrinkles, it is placed ____________; thermostatically controlled bath used to remove wrinkles/folds & to flatten the ribbon

Floatation Water Bath

remove wrinkles/folds and to flatten the ribbon

Float out bath

Float Out Bath Temperature: ___ lower than the wax melting point or between

5-10 degrees

Float Out Bath Temperature ________

45 to 50 degrees celcius

Paraffin oven: keep wax melted with temp of

2-5 degrees

Paraffin oven: higher than the wax melting point ____

55 to 56 degrees celcius

removal of ribbons from the float out bath / process of removing ribbons from the float out bath

Fishing out

process of placing ribbon in a precise position

Orientation

To promote attachment, to prevent detachment of ribbons from slide

Adhesive

Drying of Slides: Leaving slides in ____ incubator overnight

37 °C

Drying of Slides: Placing an oven

50-60 °C (2 hours)

Drying of Slides: using a hot plate

45-55 °C (30-45 minutes)

promote attachment to prevent detachment

Adhesives

routine tissue adhesive (equal amount s of egg white and glycerin + thymol crystals to prevent growth of molds

Mayer’s egg albumin

prevent growth of molds

thymol crystals

adhesive recommended in immunohistochemistry

Poly-L-Lysine

used for cytology

APES - 3-aminopropylthriethoxysilane)

commercial syrup 1:10 dilution With strong adhesive property

Sodium silicate

required: freezing microtome; use of freezing agent to immediately harden fresh tissues for immediate cutting.

Cold knife

point in which section may be cut at 10 um

Dew Line

Methods of freezing

Liquid nitrogen: used in histochemistry and most rapid Isopentane: cooled by liquid nitrogen– liquid at room temperature Aerosol sprays (cryokwik) Carbon dioxide gas: often used when using a freezing microtome Dry ice Freon 2.2– high thermal conductivity

used in histochemistry and most rapid

Liquid nitrogen

cooled by liquid nitrogen– liquid at room temperature

Isopentane

used in histochemistry and most rapid freezing

Liquid nitrogen

often used when using a freezing microtome

Carbon dioxide