Dear Katri,
Acidified solutions of Formaldehyde had  been used extensively in Histo  and
the tanning industry before World War 2, even Formal Saline contains as much
2% Formic acid in the stock formaldehyde depending upon source and grade.
Crosslinking does still occur and appears to be unaffected. Like every one
else, I detest formalin pigment which is the only drawback I know for this
Fixative/Decal reagent.
regards Mike Rentsch (Downunder)
--Original Message-----
From: Katri Tuomala <katri@istar.ca>
To: Mick Rentsch <ausbio@nex.com.au>
Cc: Hagerty, Marjorie A. <mhagerty@emc.org>; histonet@pathology.swmed.edu
<histonet@pathology.swmed.edu>
Date: Friday, 13 November 1998 4:03
Subject: Re: bone marrow trephines


>Mick Rentsch wrote:
>>
>>  Dear Marjorie,
>> we've been using FormalSaline/Formic Acid for more years than I can
remember
>> on all our trephines. At the time of Aspiration we put the trephine
directly
>> into this Fixative/Decal for a minumum of four hours, but more often then
>> not it's about 8 -10 hours as we normally do our own trephines at about
>> 0800hrs. At four hours decalcifying is close to complete, and even though
>> sometimes a bit "crispy" you can still get good sections. If you leave
the
>> trephines overnight in this Fixative/Decal, there doesn't appear to be
much
>> deterioration and detail is still excellent.
>> It may well be that any acid decalcifying agent will be adverse for your
>> studies including Trichloracetic Acid, while I've only used EDTA on rare
>> occasions and then only to ensure the best possible detail, I only did so
>> for PSA and AcP, which were excellent but required two days to decalcify
the
>> trephines.
>> The recipe I use for  5 LitresFormal Saline/Formic Acid is as follows:-
>> Sodium Chloride Analar 42.5g
>> Formaldehyde 38/40% Analar 500mls
>> Formic Acid 90-95% Analar 1600mls
>> Make up to 5 litres with RO Water >4MOhm.
>> Label as UN2810 Corrosive Liquid N.O.S. Decal Reagent. Give a two year
>> expiry and pack in 1 Litre DGA approv'd bottles.
>> Decant 35mls/ 70ml specimen jar labelled expressly for Bone Marrow
>> Trephines.
>> Hope this is of some help, Regards
>> Mike Rentsch (Downunder)
>>
>> -----Original Message-----
>> From: Hagerty, Marjorie A. <mhagerty@emc.org>
>> To: Histonet <histonet@pathology.swmed.edu>
>> Date: Friday, 13 November 1998 8:29
>> Subject: bone marrow trephines
>>
>> >
>> >Histonetters,
>> >We are currently using RDO for one hour to decal our BM core bxs. This
>> works
>> >perfectly for us, they are easy to cut, and the nuclear detail is
>> excellent.
>> >I think, however, that the HCL in the decalcifier may be interfering
with
>> >our Kappy/Lambda immunoperoxidase staining. I tried an antigen retrieval
>> >solution specifically for decalcified tissue but that did not seem to
>> >correct the problem. Doing this on one case does not count as any kind
of
>> >"study" so this may be an excellent product. We would like to try a
non-HCL
>> >decalcifier. Alex metioned formal citrate but our clinicians would not
>> >tolerate the length of time it takes. Does anyone know of a decalcifier
>> that
>> >takes no more than an hour for very small core bxs and does not use HCL?
>> >Thanks
>> >Marg
>> >EMC, Rancho Mirage, CA
>> >
>
>Hi Mike (Downunder),
>We use the same decalcifying solution you do, but always do a complete
>fixation in 10% formalin first. I was always taught that the complete
>fixation is a must before decalcifying. Is there a reference to this
>fixative/decalcifyer and how it actually works? Obviously it is not
>destroying your bone biopsies, but does the formalin still form
>crosslinkages under these conditions therefore requiring some type of
>epitope retrieval before doing IHC? It is funny, I've been working with
>this solution for several years, without really questioning the role of
>the formaldehyde in it, except that I was told it is there to prevent
>tissue destruction in case the fixation was not quite complete. I enjoy
>the cans of worms the Histonet opens! Live and learn!
>Sincerely, Katri (Canada)
>