Joyce is right about polymers hardening with time and heat.  Cold can actually
inhibit polymerization, heat can accelerate polymerization, which may explain
why putting your block into the heated water bath works better than cooling
sometimes.
Patsy

"Weems, Joyce" wrote:

> Let me say this about recutting later......I discussed this with Ada Feldman
> of Anatech several years ago. It would seem that the polymers harden more
> with time than with cold, therefore allowing for better sections later. You
> don't have to cut slowly for the recuts - just whack them off and most
> likely they'll be ok.
>
> I have found this to be one of the most frustrating of artifacts ever to
> deal with!
>
> Another thing I found good was putting the block in the warm water bath for
> a few seconds, then cooling and sectioning. The warm water seemed to work
> wonders. The slow...... steady turning of the microtome is essential for the
> first cuts of these creatures, tho.
>
> My 2 cents! j:>)
>
> Joyce Weems
> Pathology Manager
> Saint Joseph's Hospital of Atlanta
>
>         -----Original Message-----
>         From:   Bryan Hewlett [SMTP:bhewlett@cogeco.ca]
>         Sent:   Thursday, April 25, 2002 12:56 PM
>         To:     SEENRD@aol.com; histonet@pathology.swmed.edu
>         Subject:        Re: GI biopsy blues
>
>         Donna,
>
>         We process and cut large numbers of GI biopsies daily in three group
> laboratories. Only one lab has a processor dedicated to GI biopsies, the
> other labs process along with the routine surgicals. All three sites
> sporadically have some days with microchatter(venetian blinding). All sites
> use NBF for fixation, all use the same processing reagents, all cool the
> blocks on ice trays, no ammonia water.
>         This cuttting artifact is independent of processing times, it is
> seen more readily after short(less than 4 hours) fixation times in NBF.
> After all, the shorter the time in NBF the greater the fixation in
> processing alcohols!  But the cause is still operator and workload
> dependant.
>         The effect is mainly seen on very busy days with technologists who
> are under pressure, either real or imagined, to 'get the work out'. In every
> case, when the block has been re-cut and the same operator instructed to cut
> SLOWLY, the microchatters have been absent!!
>         I would recommend that when any tech in your lab has a microchatter
> episode with a case, carefull, SLOW, re-cuts of the block will solve the
> problem.
>
>         Regards
>
>         Bryan
>
>         Bryan R. Hewlett
>         Technical Specialist
>         Department of Anatomical Pathology
>         Hamilton Regional Laboratory Medicine Program.
>         Ontario, Canada
>
>                 ----- Original Message -----
>                 From: SEENRD@aol.com 
>                 To: histonet@pathology.swmed.edu
> 
>                 Sent: Wednesday, April 24, 2002 5:53 PM
>                 Subject: GI biopsy blues
>
>                 Hi Everyone,
>
>                 I am faced with some GI microchatter that has occurred
> recently.  This is a sporadic matter but as of this afternoon, I am
> currently ensued in a battle with my lab manager over the soaking of blocks
> in ammonia water. She thinks everything needs to be soaked, I say it is not
> necessary but she is insistent and I want to change her mind. I see no need
> to expose myself to ammonia fumes unecessarily.
>
>                 I have one tech that soaks everything in ammonia water and
> there is no difference between her slides and the ones I cut that are faced
> and placed onto wet ice. I am literally at wits end regarding this subject
> and do not want to submit to "ingesting" ammonia water if at all possible.
> Are there any articles written on ways to prevent microchatter? One last
> thing I should mention is that we process our GI biopsies along with our
> other larger samples (breast, colon, thyroid, etc) and everything else comes
> out looking great.  I am not at work at the moment and can't remember our
> processing schedule right of the top of my head but the solutions we are
> using is as follows: formalin x2, 80% ETOH, 95% ETOH x2, ABS x3, xylene and
> of course infiltrating with paraffin. I will post the exact scheduling and
> temps later as I can't recall those now.
>
>                 Any suggestions would be appreciated! Thanks in advance,
>
>                 Donna Barlow
>                 Section Head, Raleigh Community Hospital
>