lung in paraffin
I have never used a slide drier, but I have had some good results with
lung tissue. If adhesion is your main problem, you could try using coated
adhesive slides or charged slides. Just about any histology supplier who
sells slides will also sell some type of adhesive or charged slides. The
cost is a bit higher than for regular slides, but the time you spend trying
to persuade your lung sections to behave is probably more expensive than the
coated or charged slides are.
Some people use gelatin adhesive in their water flotation baths. These
products are usually protein based. Some adhesives and some coated slides
will cause some background staining, particularly with some special stains or
with immunohistochemistry (IHC) stains. Proteins are a vital part of IHC
staining, so adding proteins to slides to be IHC stained can cause poor
results. In my experience, H&E stains are usually unaffected by the
In my lab, we rarely use adhesives and we dry our slides in plastic
racks in the microwave for 4 minutes on power level 4. This causes the
sections to stick so well that residual sections on the back of the slide are
very difficult to clean off during coverslipping.
When I was having trouble sectioning some lung I had processed on a 12
hour cycle, I found using a vacuum very helpful. I had a metal beaker full
of melted embedding paraffin, I put the tissue in the beaker, and placed the
beaker in a vacuum dome. I left the tissue in the vacuum dome at, I believe,
20 PSI (not higher because I did not want to damage the tissue), until the
paraffin began to solidify. The vacuum caused a considerable amount of
bubbling as the air escaped the tissue and improved the paraffin
infiltration. If there was still a lot of bubbling as the paraffin
solidified, I would melt it again in the 60 degree C oven and repeat the
vacuuming. This also helped with some problematic pancreas samples I had.
After vacuuming and reembedding, the tissues cut beautifully.
Good luck with your tissues and with your new career!
Kim Atkin HT (ASCP)
Histology Lab Supervisor
Angell Memorial Animal Hospital
350 Huntington Avenue
Boston, MA 02130
Date: 11 Nov 2000 23:45:05 -0600
From: "The Robertsons" <firstname.lastname@example.org>
Subject: lung in paraffin
I have a question concerning lung in paraffin.
I am very new to histology (about 1 month) and I have been practicing with
paraffin. I have some autopsy tissue (heart, kidney, liver & lung) that I
have been running on a 14 hour processing schedule (1 hour for each
Everything is going great except for the lung.
When I put the slides in the slide dryer (a Shandon Lipshaw slide dryer) the
lower section shrinks up. I have flipped the slides around to see if I could
stop it and all that accomplished was getting both of my sections to shrink.
I have tried to keep them from getting to hot by not leaving them in for too
long. That helped with the shrinking but I lost a lot of the sections during
The closest I have been able to come to the results I want; I accomplished
using a hot plate instead of the dryer. So I think it may have something to
do with the way the air flows through the dryer.
So if anyone could please tell me if this is normal for lung tissue, if I
am over processing, or if I just have to find the perfect time in the slide
dryer I would really appreciate it.
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