Bright Instruments
23
6. Frozen Sectioning:
Problem Solving Guide Cont.
6.5 UNEVEN THICKNESS ACROSS
SECTION
a.
Specimen loose in holder.
a.
Clamping screw too loose.
a.
Blade not sharp enough.
a.
Blade edge too thin.
a.
Cutting motion uneven.
6.6 VERTICAL SCORE MARKS ON
SECTIONS
a.
Blade edge nicked or chipped?
b.
Blade faces have built up debris or frost.
c.
Anti-roll plate edge damaged?
d.
Anti-roll plate surface has debris or frost
built up.
e.
Tissue contains hard, fine particles (eg:
bone fragments).
6.7 SECTIONS CURLING
6.7.1 SECTIONS CURL OVER ROLL PLATE
a.
Anti-roll plate too low?
6.7.2 SECTIONS CURL UNDER
ANTI-ROLL PLATE
a.
Anti-roll plate at too large an angle to blade
6.7.3 SECTIONS CURL UNDER AND STICK
TO ROLL PLATE
a.
Anti-roll plate too warm, greasy
6.7.4 SECTIONS CURL AFTER LIFTING ROLL
PLATE
a.
Movement too quick, delay in collecting
sections
6.8 SECTIONS FAIL TO FLATTEN AND
PASS DOWN BLADE
a.
Anti-roll plate too warm, greasy or
misaligned
b.
Blade surface has built up frost or debris or
is too warm.
6.9 CUTTING TEMPERATURES
Standard textbooks on histological technique
give table of recommended cutting
temperatures for different tissues. However, in
most cases the following guidelines will prove
adequate.
Fresh, infixed tissue
Most soft tissues will cut at -18ºC to –20ºC.
fatty tissue such as breast lumps will
need lower temperatures, -25ºC or colder.
Brain and spinal cord cut best at warmer
temperatures, eg; -12ºC
Fixed tissue
Differences between tissues are much reduced
after fixation. Cutting temperatures around
–10ºC to –15ºC are recommended, but some
experimenting may be required. Ensure
fixative is rinsed off tissue before freezing.
