Re: Formalin substitutes

From:Amos Brooks

Hi Valerie,
    I say stick with what works. Does that mean other fixatives don't work? ... No, but 10% neutral buffered formalin is the standard. This is what the manufacturers test the antibodies on, it is how tissues are *routinely* processed it is the industry standard. Now obviously it is not the best fixative, primarily due to it's toxicity and the amount of pretreatments necessary for IHC to work, but it is what everyone (OK ... almost everyone) uses.
    If as a RULE or an international STANDARD, EVERYONE chose ONE alternative fixative then it would make sense to ditch formalin and life would be happy. But honestly, I don't see any standards forthcoming. In fact quite the opposite, I see dozens of companies competing, each with their own nonsensical "proprietary" (there's that P-word again) formulation.
    So if you did switch to another fixative and optimized all your IHC procedures to match your choice of fixative how would you deal with a consult block that you might get that you did not process and would it be properly standardized. Or on the other hand how would another lab that gets a block you processed in this fixative. How would they know how you and all the other blocks they might get were processed. How should their controls be processed. (Good luck finding an ALK1 (+) control processed 12 different ways (just in case)) It's really just a question of standardization. Aldehydes aren't the best but like it or not, they are the standard.
Amos Brooks
----- Original Message -----
From: Valerie Hannen
To: histonet
Sent: Wednesday, May 29, 2002 11:21 PM
Subject: Formalin substitutes

Hi,
 
It's me again.   We currently use zinc formalin. Our safety officer wants us to check into formalin substitutes. My problem is that our IHC procedure (Kit from manufacturer)
says to use only formalin, or zinc formalin for best results.
 
Any input would be greatly appreciated.
and no we don't want to change our IHC procedure.
 
Thanks a lot!!!!
 
Valerie Hannen,MLT(ASCP),HTL
Parrish Medical  Center
Titusville, Florida
32796
 
 

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