5 poor processing – correct protocol, Poor processing – correct protocol – Leica Biosystems PELORIS_PELORIS II User Manual
Page 145

Troubleshooting
Leica PELORIS™ User Manual Rev K © Leica Biosystems Melbourne Pty Ltd 2011
145
9.2.5 Poor Processing – Correct Protocol
Poor processing –
correct protocol
Did the
processor
malfunction or
error?
Was
tissue
over-exposed
to solvents/
wax?
Over-processed.
Reprocessing will not
help
Did the
tissue dry out
completely?
Reconstitute and
then reprocess
Were steps
skipped?
Were
contaminated
reagents
used?
Was the
incorrect
reagent used in
processing
sequence?
Yes
Yes
Yes
Do blocks
contain
hard fragment
that shred
segments?
Is it
calcium?
Reprocessing will not help. Decalcification
is required. Surface decal can be performed
by trimming the block in gently and then
placing the block face down on a
decalcifying medium.
Try a softening agent, such as fabric softener, at
sectioning. If it is a foreign body such as a staple, melt
block down, remove object and re-embed
Adequately
processed tissue
Yes
No
No
No
Yes
Yes
No
Tissue is poorly processed. Reverse
process to formalin, reconstitute and
then reprocess
Is it delicate
tissue?
Is it large
robust tissue?
Is it fatty
tissue?
Try a longer,
more gentle
process. Less
heat and
agitation.
Try a longer,
protocol with
more heat and
efficient agitation.
Try a defatting step of
50/50 xylene and
ethanol. Put step
between ethanols and
xylene, ensuring that
there is a 100% ethanol
step after defat, before
xylene.
After
reprocessing
is tissue processed
adequately?
Yes
No
No
Yes
Yes
No
Attempt soaking the
block before cutting.
Did the tissue
dry out during
processing?
Reverse process to
formalin, reconstitute
and then reprocess
Yes
No
No
No
Yes
Yes
Is tissue
adequately
processed
No
Yes
Adequately processed
tissue
Is it xylene
processing?
Yes
No
NB: Do not use the Peloris clean cycle to
reprocess the tissue as the drying step
will cause the tissue to dry out