Hmm

Well I've done this on several occasions and had excellent processing as a
result.
Companies tend not to recommend that you do anything other than what is in
the manual as they are worried about liability.
As long as you use quality reagents it's never been a problem here.
We also use this "reverse processing" method for dealing with under
processed tissue that requires re-processing, especially fatty tissues.
It has always worked very well, with good preservation of morphology and
antigenicity.

It works for me and many other labs in the UK who I know use it.
As for temperature of 45 degrees being too high.
Well molten wax is over 60 degrees centigrade so if anything is going to
cook tissue that will.
I think the "cooking" issue is a spurious argument especially when you
consider people routinely microwave tissue as well as use heat mediated
antigen retrieval that basically boils the tissue, yet morphology and
antigenicity are maintained.

Just passing on my experience.

Nick Kirk
Hinchingbrooke Hospital
Huntingdon
England

-----Original Message-----
From: connie grubaugh [mailto:conniegrubaugh@hotmail.com]
Sent: 17 July 2003 03:39
To: nick.kirk3@btopenworld.com
Subject: RE: Processor failure


I just want to put in my 2 cents worth and do not put your tissue on the
flush or purge cycle on your machines.  I have done this and the tissue was
bad.  After talking to the representatives of the companies they do not
recommend this the temperature is too high and will cook your tissue.
Connie Grubaugh
Las Vegas Nv.


>From: Nick Kirk 
>To: Joey Wilkie 
>CC: histonet@pathology.swmed.edu
>Subject: RE: Processor failure
>Date: Wed, 16 Jul 2003 23:38:14 +0100
>
>Processor failureOh dear, sounds like a bit of a disaster.
>My advice would to "reverse process".
>The most important thing you need to do is remove any wax that is present
>in
>the tissue. There is bound to be a small amount of impregnation even after
>what the tissue has been through.
>This is essential before any repeat processing is attempted.
>I would put the blocks through the "flush cycle" on the VIP, i.e. xylenes
>(or substitute) followed by alcohols, preferably at 45 degrees centigrade,
>to ensure complete wax removal and impregnation by the alcohol.
>This should get your tissue back to a state where it can then be
>re-hydrated
>safely with minimal tissue damage.
>Fixation would not appear to be a problem so you could miss that step out
>when you re-process to speed things up a bit.
>
>Good luck
>
>Nick Kirk
>Head Biomedical Scientist
>Histopathology
>Hinchingbrooke Hospital
>Huntingdon
>England
>   -----Original Message-----
>   From: Joey Wilkie [mailto:JWilkie@stmarygj.com]
>   Sent: 16 July 2003 17:38
>   To: 'histonet@pathology.swmed.edu'
>   Subject: Processor failure
>
>
>   Last week our embedded came in to embed and found that the tissue was
>not
>fixed.  After some investigation, we found that the some of the carbouys on
>the processors had been misplaced.  Our tissue had gone through a 10%
>formalin, a 100% alcohol , 50% alcohol , 80% alcohol , two 95% alcohols,
>100% alcohol, back into a 10% formalin and then into two xylenes, and then
>into four paraffin baths.  We are using a VIP processor.
>
>   Now the question is how do we go about reprocessing the tissue.  Any
>help
>that you can give us would be greatly appreciated.
>
>   Thanks, Joey
>   St. Mary's Hospital
>   Grand Junction, Colorado
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