Re: Non formalin fixatives

From:Amos & Theresa <atbrooks@snet.net>

Hi,
    Speaking as someone recently from a similar reference setting, I will put my
money on a resounding NO. The forms filled out by the clients are usually
incomplete not mentioning the fixative they decided to use, and it is virtually
impossible to keep a control bank of all tissue types with such a variety of
processing. The controls used are most probably (And please note I don't work
there so I said "PROBABLY") Formalin fixed paraffin embedded. Lets look at a
short list of the possible combinations these people would need to keep a full
tissue bank of ...

formalin / xylene, bouins / xylene, Prefer / xylene, histochoice / xylene
formalin/ histoclear,  bouins / histocclear, Prefer / histoclear, histochoice/
histoclear

    From here I think you can see that there are an infinite number if variables
that can occur. It is virtually impossible to maintain a tissue bank of this
size, and then have a different procedure for each weather or not you actually
even know what conditions the tissue was processed under. Can you imagine the
size of such a procedure manual?
    When sending a tissue it is best to contact the company and ask them what
conditions they are using. If it is a problem then speak to them and see if a
deal can be worked out. But sending a tissue fixed and processed under whatever
conditions and then expecting each case to be run under a different procedure is
basically logistically impossible. The FDA was well aware of this when allowing
the Herceptest to be approved. That is why the regulations are so stringently
outlined.
    The moral of the story is when sending tissue to an outside lab, stick to
the basics ...FFPE. You can't go wrong.

Jeff Silverman wrote:

> Interesting thought Vinnie. We use HistoChoice fixative. Like most other
> antibodies, for ER and PR- using HistoChoice obviates the need for any type
> of antigen retrieval, enzyme or heat. I'm currently getting started with the
> Cytologix ER and PR antibodies on my Artisan stainer and they should be
> beautiful if the other antibodies are any indication. We now send
> ER/PR/HERCEPT to Impath and they have been fine. Impath mounts their
> controls, which I assume are formalin fixed, on the patient's slide. I
> wonder if they are unnecessarily nuking my HistoChoice fixed tissues along
> with their controls, or do they use HistoChoice controls for us few
> HistoChoice clients. The sections look nuked to me. Anyone from Impath care
> to answer? Anyway, I would assume that HistoChoice would obviate the need
> for HIER on Hercepts. If anyone wants to loan me a few drops of a Hercept
> antibody, I'll test it.
> Jeff Silverman
> Southside Hospital




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