Instrumentation in Histopathology (MICROTOMY) Flashcards
When there is rapid diagnosis
Freezing Microtome
temperature in a cryostat
5 to -30°C
(-20°C)
When histological demonstration of fat is needed
Freezing Microtome
Most dangerous type of microtome
SLIDING MICROTOME
Especially recommended for cutting extremely hard and
rough tissue blocks
SLIDING MICROTOME
Comparatively more stable than the sliding microtome
seen previously
Base-sledge Microtome
continuous sections
Serial sections
When sensitive tissue constituents to be studies are
damages are destroyed by heat
Freezing Microtome
Consists of microtome kept inside a cold chamber which
has been maintained at a temperature between -5 to -30°C (-20°C) by an adjustable thermostat
Cryostat
It has a movable exposed knife (moves up/down)
SLIDING MICROTOME
When certain neurological structures are to be studied
Freezing Microtome
Also known as sectioning
MICROTOMY
Dual purpose microtome can produce:
■ Rapid freezing sections for RFS
■ Routine paraffin sections for routine histopathology
lab tests
Computerized Microtome
Can cut sections of 4μ with ease
Cryostat
The blade is placed in a blade-up position which is relatively dangerous
ROTARY MICROTOME
Causes reciprocal motion of the knife over the block
flywheel
must be brushed away with soft brush and not allowed to stay in the microtome
accumulated paraffin and small pieces of tissues
Most commonly used for rapid preparation of urgent tissue biopsies for intraoperative diagnosis
cryostat
2 kinds of sliding microtome
- Base-sledge Microtome
- Standard sliding microtome
Consist of a heavy base and two arms
ROCKING MICROTOME
Cuts the block at a predetermined thickness. It
produces tissue ribbons that are connected to each
other
Knife
Invented by Queckett in 1848
FREEZING MICROTOME
After drying the machine and knifeh older, the parts should be wiped with
xylol
More dangerous than Base-sledge
Standard Sliding Microtome
Simplest among the different types of microtome
ROCKING MICROTOME
cryostat Provides a means of preparing thin sections of fresh
frozen tissues for ________________ or _____________
- fluorescent antibody staining techniques (immunohistochemistry)
- histochemical enzyme studies (microstructure and enzyme/antigen integrity)
Most common type used for both routine and research
laboratories
ROTARY Microtome
Line up the tissue block in the proper position
Adjustment screws
Difficulty of reorienting the block
ROCKING MICROTOME
Developed by Adams in 1789
SLIDING MICROTOME
Developed mainly for cutting celloidin-embedded
tissue blocks
Standard Sliding Microtome
Designed for non-contact sectioning inside biological
tissues without causing thermal damage
Laser Microtome
Can be used for paraffin wax and for tougher embedding
materials like celloidin (resinous / plastic-like medium) and
nitrocellulose (some kind of polymer)
SLIDING MICROTOME
Primarily used for cutting tissue sections at 0.5 micra for
electron microscopy.
Ultrathin Microtome
are used to mount tissues in the Cryotome
OCT
The knife used for cutting the ultrathin sections consists mainly
of selected fragments of broken plate glass.
Consist of two movable pillars holding the adjustable
knife clamps, allowing the knife to be set at an angle
for cutting celloidin sections
Base-sledge Microtome
cryostat is Capable of freezing fresh tissue within how many minutes
2-3 minutes
or lowering temperature of the
knife to facilitate sectioning in frezzing microtome
second cooling device
in Ultrathin Microtome, The specimen used is small, fixed in ___________, and embedded in ______
- osmium tetroxide
- plastic
Suited for sectioning specimens embedded in all forms
of media
Base-sledge Microtome
The stage for block holder is hollow and perforated around
its perimeter, attached to a reinforced flexible lead pipe
through which carbon dioxide (freezing agent) passes
from a cylinder
FREEZING MICROTOME
Designed to cut sections from very hard materials like
undecalcified bone, teeth, glass, and ceramics
Saw Microtome
Restrictions in size of tissue block that can be cut
ROCKING MICROTOME
Invented by Minot in 1885-1886
Minot Microtome
is brought into contact with, and turns a ratchet feed wheel connected to a micrometer screw, which in turn rotated, moving the tissue block at a predetermined distance towards the knife for cutting sections at uniform thickness
spring balance teeth or pawl
Invented by Paldwell Trefall in 1881
Cambridge rocking microtome
The block remains stationary while the knife is moved
backward and forward during the process of sectioning
Standard Sliding Microtome
Operated by the rotation of the flywheel
ROTARY MICROTOME
sometimes included
Copper mesh grid
in the ROTARY Microtome, the Thickness of the section being automatically regulated
by the
ratchet feed wheel
Favored in laboratories where very hard tissue or large
blocks are usually sectioned.
Base-sledge Microtome
Uses high-speed vibrations produced by safety razor
blades which provide the cutting power, allowing the
resultant cut to be made with less pressure than would
the stationary blade be
Vibrating Microtome
Mostly used for rigid botanical materials
Hand Microtome
allows the release of rapid intermittent burst of carbon dioxide in freezing microtome
simple lever operated valve
Adjust the thickness for the sections
Adjustment screws
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
Not recommended for serial sections because tissues are
cut in slightly curved planes
ROCKING MICROTOME
Holds the tissue
Chuck/block/tissue block
The knife and the block holder are brought together by
upward and vertical motions
ROTARY MICROTOME
Used to cut undehydrated tissues in a frozen state
Freezing Microtome
