Hi Phil


It was phenomena that I only started to see when I started 
to work at my present establishment. 

Your problem may be due to the block being too "dry"    
Staff here always insisted on cooling the blocks on wet ice 
prior to cutting the section it made the problem disappear. 
I can only attribute this to the processing schedule which 
was designed to deal with the rather generous samples that 
some pathologist would try to sneak into the cassettes!!

I also found the same problem with large blocks of gut and 
liver   It improves them as well.

This can not be applied all blocks when I was doing some 
reasearch using blocks provided by another department I had 
to place the blocks in the fridge otherwise the blocks take 
in water and the tissue would stand proud of the wax making 
it very difficult to cut

Regards

Wendy

On Fri, 30 Jul 1999 14:29:41 +0100 "Hall, Phil" 
<Phil.Hall@ubht.swest.nhs.uk> wrote:

$ Does anyone see microscopic chatters (cracks parallel to the knife edge) in
$ endoscopy biopsies (approx 0.2cm diameter)?  
$ 
$ We have been seeing these in our paraffin sections of these biopsies so
$ badly that the Pathologists sometimes complain it makes diagnosis difficult.
$ We do not seem to have any problems with large tissue blocks or bone.  We
$ cut sections at 3 microns using a manual rotary microtome with disposable
$ S35 blades.  
$ So far we have done the following to try to stop this happening:
$ 
$ changed microtome - including buying a new one
$ changed blades - including using a different supplier
$ changed the microtome knife angle
$ cut them slower and faster
$ cut them very cold or warm
$ let them float on the water bath for longer or picked them up straight away
$ 
$ Any other ideas?
$ 
$ 
$ Phil Hall
$ Paediatric Pathology
$ St Michael's Hospital
$ BRISTOL
$ UK
$ 

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