[Histonet] Help

[Joseph Saby]

Kathy-

What do these cracks look like?  Are they arranged in a parallel manner?  Or do 
they have the appearance of the cracks seen in dry mud?

Parallel aligned cracks are often found in overprocessed small biospies.  These 
small samples become hard and brittle.  The impact of the tissue on the 
microtome blade during aggressive facing force these cracks deep into the 
tissue.  With care, patience and some luck you may be able to get beyond these 
cracks by soaking the blocks, facing with thin sections on a repeated basis.  
What will determine whether you are successful will be whether there is enough 
depth to your biopsy to allow you to get beyond the facing artifact.

If the cracks resemble dry earth, then we are looking at a fixation/processing 
issue.  These cracks do not appear in the tissue until the xylenes after slide 
staining.  If the tissues are not well fixed, then processing reagents will not 
be able to fully penetrate the tissues.  If possible, I would suggest you 
perform retrims on your tissue and process them normally.  They should have had 
enough time to fix when you do your retrims, and they should be fine.  In a 
hospital setting, this may not be possible.  You can deparaffinze and rehydrate 
your tissue samples by running them through your processor's cleaning program.  
Place them back in fixative for a while, then reprocess them.  


I have also seen this artifcat in tissue when (due to a processor malfunction) 
tissue samples were exposed to high heat during processing.  Look for blood 
cells being "laked" in the larger blood vessels (blood cells look like a 
homogenous mass rather than being able to cell boundaries).  Sometimes there 
will be small round black precitate granules over the affected tissue areas.  
You will need to determine the best course depending on the extent of the 
damage.  Extensive damage will probaly require retrims. 

I hope this helps.  Please get back with me if yoiu have any further questions.

Joe Saby, BA HT
37 years in histotechnology


________________________________
From: Kathy Nelson <kathyenelson <@t> hotmail.com>
To: Histonet <histonet <@t> lists.utsouthwestern.edu>
Sent: Sun, December 19, 2010 1:25:54 AM
Subject: [Histonet] Help


Solutions for cracks in tissue microscopically esp. in tumors and BCC specimens.
Thanks 
kathyenelson <@t> hotmail.com                         
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