Instrumentation Flashcards
- carousel-type
- 9-10 rgt positions
- 2-3 wax positions
Tissue-Transfer processors
capacity: 30-110
Tissue-Transfer processors
transfer of tissues, container within a basket through a series of stationary reagents arranged in-line or in a circular carousel plan
Tissue-Transfer processors
processing fluids pumped to and from a retort in which tissues remain stationary
Fluid-Transfer processors
- 10-12 rgt statiosn with adjustable temperature (30-45º)
- capacity: 100-300 cassettes
Fluid-Transfer processors
- only used in histopath labs with moderate to heavy workloads
- for easy preparation of tissue blocks
Tissue Embedding Center
Tissue Embedding Center
instant cooling of the exchange plates
Freon Refrigeratory System
Tissue Embedding Center
- forms penthouse that contains molten paraffin
- has a microswitch dispenser (lower left of the penthouse)
- maintains paraffin optimal temperature
- with adjustable thermostatic control
Paraffin Melting Chamber
Tissue Embedding Center
filters particles & sediments
microscreen
Tissue Embedding Center
provides a non-clogging flow of molten paraffin for the casting of the molds when the plate is gently pressed
Microswitch dispensers
Tissue Embedding Center
“hot & cold plates”
Hot & Cold Orientation platforms
Tissue Embedding Center
for different operations of the embedding procedure
Hot & Cold Orientation platforms
Tissue Embedding Center
catches excess paraffin
waste drawer
Tissue Embedding Center
to preheat forceps
hot well
Basic instrument used that is capable of cutting section at a predetermined thickness by sliding the block into a cutting tool which is fixed and attached to the machine
microtome
Microtome Parts
Where the tissue is held in position
block holder
Microtome Parts
For actual cutting of tissue sections
knife/knife carrier
Microtome Parts
To line up the tissue block in proper position with the knife, adjusting the proper thickness of the tissues for successive sections
- Pawl
- Ratchet Feed Wheel
- Adjustment Screws
Types of Microtomes
- oldest type
- simplest
rocking microtome
Types of Microtomes
- invented by Paldwell Trefall in 1881
- Used to cut small and large blocks of paraffin tissues
- Not recommended for serial sections because tissues are cut in slightly curved planes
Rocking microtome
Types of Microtomes
“Minot microtome”
Rotary microtome
Types of Microtomes
invented by Minot in 1885-1886
Rotary microtome
Types of Microtome
- operated by rotation of the flywheel
- most common type used for routine and research laboratories
- sectioning paraffin-embedded tissues
Rootary microtome
Types of Microtome
developed by Adams in 1789
Sliding microtome
Types of Microtome
- recommended for cutting extremely hard and rough tissue blocks
- most dangerous type of microtome because it has a
movable exposed knife
Sliding microtome
Sliding Microtome
- two movable pillars holding the adjustable knife clamps, allowing the knife to be set at an angle for cutting celloidin sections
- suited for sectioning specimens embedded in all
forms of media- cutting sections from tough tissue blocks
Base-Sledge microtome
Sliding Microtome
block remains stationary while a knife is moved backward and forward during sectioning
Standard sliding microtome
Sliding Microtome
developed mainly for cutting celloidin-embedded tissue blocks
Standard sliding microtome
Types of Microtomes
invented by Queckett in 1848
Freezing microtome
Types of Microtomes
designed for cutting frozen sections
Freezing microtome
Types of Microtomes
- a lever-operated valve allows the release of rapid intermittent burst of CO2
- provides a means of preparing thin sections of fresh frozen tissues or fluorescent antibody staining techniques or histochemical enzyme studies
Freezing microtome
Types of Microtome
most commonly used for rapid preparation of urgent tissue biopsies for intraoperative diagnosis
Freezing microtome
- cryotome
- deisgned by Linderstrom-Lang & Mogenses in 1938
cryostat
- a microtome kept inside a cold chamber
- (maintained at -5 to -30ºC by an adjustable thermostat)*
- usually seen in Rotary Microtomes
- (preferably rustproof)*
cryostat
Types of Microtome
“ultramicrotome”
Ultrathin microtome
Types of Microtome
primarily used for cutting tissues at 0.5 micra for electron microscopy
Ultrathin microtome
Ultrathin microtome’s knoves are usually made of?
- glass
- diamonds
- sapphires
Types of Microtomes
- block is brought to the edge to the knife-edge under microscopical control
- sections are placed in a water bath adjacent to the knife-edge
Ultrathin microtome
Types of Microtomes
designed to cut sections from fresh unfixed materials from animal or botanical sources
vibrating microtome
Types of Microtomes
high-speed vibrations produced by a safety razor blade which provides the cutting power
vibrating microtome
Types of Microtomes
sectioning for rigid botanical materials
hand microtome
Types of Microtomes
- designed to cut sections from very hard materials such as:
- undecalcified bone
- glass
- ceramics
- samples are embedded in resin
saw microtome
Types of Microtomes
- moved extremely slow against a diamond-coated saw rotating @ 600 rpm
- cannot produce thin sections
saw microtome
Types of Microtome
- designed to section large blocks of tissues
- block holder is mounted on a steel carriage which slides backward and forwards on guides against a fixed horizontal knife
sledge microtome
Types of Microtomes
for non-contact sectioning inside a botanical tissue without causing thermal damage
laser microtome
Types of Microtome
equipped with femtosecond laser technology
laser microtome
Types of Microtomes
- dual purpose
- can produce rapid freezing sections or routine paraffin sections
- can produce sections from 1-245 microns
computerized microtome
Microtome Knives
25 mm in length
plane-concave knife
Microtome Knives
120 mm in length
biconcave knife
Microtome Knives
100 mm in length
plane-wedge knife
Microtome Knives
one side of the knife is flat while the other is concave
plane-concave knife
Microtome Knives
- both sides are concave
- recommended for cutting paraffin-embedded sections on a rotary microtome
biconcave knife
Microtome Knives
both sides are straight
- recommended for:
- frozen sections
- extremely hard and tough specimens embedded in paraffin blocks using a base-sledge type or sliding type
plane-wedge knife
Microtome Angles
- 27°-31°
- 15°
- 3°-8°
- 90°
- ° between block face & upper knife facet
- 27°-31° = bevel angle
- 15° = wedge angle
- 3°-8° = clearance angle
- 90° minus upper facet’s angle = rake angle
- ° between block face & upper knife facet = cutting angle
Clearance angle is best at what angle?
5°
