Formalin over fixation depresses tinctorial staining, particularly
haematoxylins. If you look in one of the old histology techniques textbooks
you should find a method for improving such weak staining. The principal
methods as I remember them involved the use of sodium dichromate, but I
don't remember the details, however if I come across them I will post them
asap. Meanwhile, I suggest you try to find a copy of a book by Culling or
Carleton's Histological Technique by Drury and Wallington, they will
probably be available in a University library or if you know someone who has
been in histology as long a I have they may have their own copy, sorry I
haven't.
Good luck

Margaret Blount
Clinical Biochemistry
Cambridge University
UK

-----Original Message-----
From: Robert Schoonhoven [mailto:rschoon@email.unc.edu]
Sent: Friday, June 27, 2003 1:38 PM
To: Tague, Curtis
Cc: Histonet (E-mail)
Subject: Re: AFB cont. tissue


If this is the case then I would just use one of the many antigen
retrieval methods developed for IHC.

Bob
Robert Schooonhoven

Tague, Curtis wrote:

>I read somewhere that if left in formalin too long there will be a problem
with staining. Something to do with a cross link blocking of a protein on
the membrane. Anyone familiar with the details of this and if this is
accurate, is there a way to reverse the action, soak in 70% or something
like that? Or, is that tissue just lost?
>
>We have a few lobes of lung that are/were all loaded but don't stain now.
>
>Thanks,
>Curt
>
>Confidentiality Note:
>
>The preceding e-mail message (including any attachments) contains
information that may be confidential, protected by applicable legal
privileges, or constitute non-public information. It is intended to be
conveyed only to the designated recipient(s). If you are not an intended
recipient of this message, please notify the sender by replying to this
message and then delete it from your system. Use, dissemination,
distribution or reproduction of this message by unintended recipients is not
authorized and may be unlawful.
>
>
>
>
>