Joseph A. Saby, BA HT
Diagnostic Pathology, Pathology & Experimental Toxicology
Parke-Davis/Int. Pharm. Res. Div. Warner-Lambert
Ann Arbor, MI 48105
Phone: (734) 622-3631
Fax:     (734) 622-5718
e-mail:  Joseph.Saby@wl.com


-----Original Message-----
From: Saby, Joseph 
Sent: Friday, July 30, 1999 10:00 AM
To: 'Hall, Phil'
Subject: RE: Micro-chatters in gastric biopsies


Phil-

Part of the problem you describe is caused by over-processing.  If possible,
you should try to set up a biopsy program on your processor (or process by
hand).  For ~1-2 mm tissue pieces, I would suggest about 15-20 minutes per
station.

Another way to deal with this artifact is through how the blocks are
sectioned.  FIRST: FACE GENTLY!!!  NO thick sections, NO fast speeds.  If
you have the artifact, it is caused during facing, when the too hard/too
tough tissue is actually smashed/ripped/compressed during facing.  The only
way to remove the artifact, if possible, is to gently face through it.
Which means, the only way to avoid it is to not cause it. If you face slowly
and take no thick sections, you will get good sections.  Soaking a little
longer on you ice bath before sectioning may well help your sections, too.

Good luck!

Joseph A. Saby, BA HT
Diagnostic Pathology, Pathology & Experimental Toxicology
Parke-Davis/Int. Pharm. Res. Div. Warner-Lambert
Ann Arbor, MI 48105
Phone: (734) 622-3631
Fax:     (734) 622-5718
e-mail:  Joseph.Saby@wl.com


-----Original Message-----
From: Hall, Phil [mailto:Phil.Hall@ubht.swest.nhs.uk]
Sent: Friday, July 30, 1999 9:30 AM
To: 'Histonet'
Subject: Micro-chatters in gastric biopsies


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