BRIGHT OTF6000, Руководство пользователя

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Bright Instruments 41
3.5 HINTS ON SECTIONING CONT.
d. Make sure that the knife and the anti-roll
plate are suitably cold. It can often help to
use a short blast of Cryospray 134 if this is
in doubt. If Cryospray 134 is used, make sure
that there is not an accumulation of rime
present on the underside and leading edge of
the anti-roll plate. Care must be taken when
using Cryospray 134. The risk of creating
an aerosol of potentially infectious tissue
particles must be borne in mind.
e. If the section is skewing, this is a sign
that the anti-roll plate is not parallel to the
edge of the knife. Remember also that the
angle of the underside of the anti-roll plate
must be parallel to the facet of the knife (but
just a little larger for the best results). If the
angle is too large, then the section will curl.
If the angle is too small, then the section will
crumple.
f. If there is any doubt that the temperature
of the microtome or cryostat chamber is not
at the right temperature, be patient and wait
for a while until the temperatures equalise.
g. For other problems follow the advice in
section 3.6 below.
3.6 FROZEN SECTIONING:
A PROBLEM SOLVING GUIDE
Cutting good frozen sections requires skill
and practice, and some tissues are particularly
difficult. In all cases the quality of the result
depends on a number of factors.
The notes which follow deal with the more
commonly encountered difficulties, and
suggest a systematic approach to problem
solving.
3.6.1 SOLUTION CHECKLIST
First check all the basic factors:
Specimen
• Was it frozen badly?
• Has it equilibrated to chamber temperature?
• Has it become loose on the specimen
holder?
• Is the specimen holder tightly clamped?
• Is the orientation lever locked? (Orientating
head microtomes only)
• Has the specimen dehydrated?
Knife
• Has it become dull?
• Is it nicked or chipped?
• Is the knife tilt angle incorrect?
• Is the knife loose?
• Is there a build-up of frost or debris on
the knife?
Anti-Roll Plate
• Is it set too high/low?
• Is the angle to the knife too wide/narrow?
• Is it parallel to the knife?
• Is it frosted/too warm?
• Is it damaged?.
General Factors
• Is the chamber temperature appropriate
to the specimen (or specimen temperature
control, where fitted)?
• Is the cutting motion too fast/slow/uneven?
• Has the microtome reached the end of its
travel?
• Is the section thickness setting appropriate?
3. Cutting & Collecting
Sections Cont.