Instrumentation Flashcards
Used by histotechnologists for QC
microscope
Microtome:
Inventor:
Purpose: cutting serial sections of large block of paraffin; simplest
Rocking
Paldwell Trefall
“Na fall ka tungod sa rock”
Microtome:
Inventor:
Purpose: cutting embedded section; most common
Rotary
Minot
“routine”
Microtome:
Inventor:
Purpose: cutting celloidin; dangerous due to movable knife
Sliding (standard)
Adams
“na slide si adam”
Sliding microtome that is ideal for resin-embedded decalcified bone
base sledge (knife is stationary)
Microtome:
Inventor:
Purpose: cutting unembedded frozen sections
Freezing
Queckett
“quick-freeze”
Microtome:
Inventor:
Purpose: EM; embedded in plastic resins using diamond/glass knives
Ultrathin
Knife: Plane concave
Length:
Info:
25 mm
less concave = celloidin
more concave = paraffin
Knife:
Length: 120 mm
Info:
Biconcave
Rotary microtomes for paraffin
Knife:
Length:
Info: Both sides are straight for frozen & very tough paraffin embedded tissues
Plane wedge
100 mm
Knife:
Info: more commonly used nowadays; eliminates honing & stropping process
Disposable knives
Knife:
Info: suitable for cryostat
Magnetic
Knife:
Length: 0.5 - 1 um
Info:
Glass knives
semi-thin survey sections
Knife:
Length: 50-120 um
Info:
Diamond knives
ultra-thin sections for EM
brittle but very durable
Process of removing the “nicks”
Heel to toe direction (20-30 double strokes)
Honing
Type of hone:
Manual sharpening but gives best results
Belgium yellow
Type of hone:
Gives more polishing effect
Arkansas
Type of hones:
much coarser & for badly nicked knives
Fine carborundum
Process of removing “burrs”, dine to polish & sharpen
Toe to Heel direction (40-120 double strokes)
Stropping (horse leather)
Used to clean microtome
soft brush & xylol
Bevel angle
27-32° angle
Causes maximum penetration of tissues & minimize distortion
Perfect & optimum angle (15°)
Angle is around 0-15° which prevents uneven sections
Clearance angle
Specimen is transferred from container to container for 16 hours
Tissue transfer (dip & dunk)
Tissues remain in one container but the reagent changes at intervals
Enclosed type tissue processor
Wax bath thermostat should be at least ___ the melting point of the wax
3° above
its the mechanically raising and lowering of the tissue into reagent containers providing agitation needed
Vertical oscillation
Stations 1-2 of autotechnicon
Fixation w/ 10% formalin
Stations 3-6 of autotechnicon
Dehydration w/ ascending ethyl alcohol 70-95%
Stations 7-8 of autotechnicon
2 changes of acetone
Stations 9-10 of autotechnicon
Clearing with 2 changes of chloroform/xylol
Stations 11-12 of autotechnicon
Impregnation w/ 2 changes of liquid paraffin
Temperature for floatation water bath
45-50°C
or 6-10°C lower than the melting point of wax used
squamous cell contaminants from ungloved fingers
Floaters
Wax impregnation under negative atmospheric inside an embedding oven & gives fastest result
Vacuum embedding apparatus
Temperature of drying oven
Infiltration process: 55-60°C
Drying process: 56-60°C for 2hrs
Glass slides for routine work
size:
refractive index:
76 x 25 mm with 1-1.2 mm thick (frosted)
1.518
Labelling in histopathology
Foolproof
