>Date: Fri, 17 Nov 2000 13:19:29 -0500
>To: Lee & Peggy Wenk <lpwenk@mail.netquest.com>
>From: ANATECH LTD <email@anatechltdusa.com>
>Subject: Re: GLYOXAL AND IHC
>Cc:
>Bcc:
>X-Attachments:
>
>>Dear Peggy,
>
>
>As one of several suppliers of a glyoxal fixative, I would highly 
>suggest the originator of the call contact technical support of the 
>supplier of the glyoxal fixative. As a supplier of a glyoxal 
>fixative (Prefer) I need to ask several questions beyond the 
>information provided to offer a solution.
>
>For example, was the tissue both received and processed in the 
>glyoxal fixative?
>Receiving in NBF and processing in glyoxal or vica versa modifies 
>the IHC protocal as one goes deeper in the block.
>
>If the tissue was not totally fixed in the glyoxal fixative, the 
>interior ofthe tissue was "fixed" with alcohol. The IHC protocal 
>will be different forthat area ofthe block.
>
>Was antigen retrieval used? Glyoxal fixatives general do not require 
>it. If antigen retrieval is used on glyoxal fixed tissues results 
>are negative.
>
>These are just a few questions. Other questions could be asked 
>depending upon the answer to the above.
>
>Sincerely,
>
>
>
>>Need some help again.
>>
>>Received a call. A histo lab has switched to a glyoxal fixative.
>>
>>When they first perform an IHC on any of the tissues, for any antibody,
>>it works great.
>>
>>If the lab goes back to the same BLOCK a couple of weeks later, and
>>cuts some more slides, the intensity of the staining is less.
>>
>>If the labs waits a couple more weeks and cuts more slides from the
>>BLOCK, there is NO IHC staining.
>>
>>Yet, the new BLOCKS (just processed) are staining great. So they know
>>that the antibodies are fine. But wait a couple of weeks on the new BLOCKS,
>>and the same decrease in staining pattern repeats.
>>
>>They thought it might be underfixation, so they have increased the
>>time in fixation, but the pattern is still repeating.
>>
>>I know about decrease of staining on previously cut/stored SLIDES.
>>But has anyone experienced this on BLOCKS, for any antibody,
>>in just a couple of weeks time? Is it a fixation/processing problem
>>in general, or is it specific to glyoxal fixatives?
>>
>>Any and all thoughts from the collective minds of Histonet are welcomed.
>>(and appreciated)
>>
>>Peggy A. Wenk, HTL(ASCP)
>>William Beaumont Hospital
>>Royal Oak, MI 48073

-- 
Ada T. Feldman
Director of Manufacturing & Technical Services
Anatech Ltd.
1020 Harts Lake Road
Battle Creek, MI  49015
800-ANATECH (800-262-8324)
email@anatechltdusa.com
Web address:  anatechltdusa.com