> Date:          Thu, 22 Jul 1999 08:02:40 -0500
> From:          "Margaret Gondo" <gondom@valentis.com>
> Subject:       formalin fixing already frozen muscle
> To:            Histonet@Pathology.swmed.edu

> Hi Folks!
> 
> Here's the "stupid" question of the day that I hope you all can answer.  I
> have some muscle tissue which I had frozen using standard techniques (ie
> gum tragacanth, pre-cooled isopentane in liquid nitrogen).  Due to some
> questions which have popped up regarding the possibility of infectious
> agents being present, I am now being persuaded to formalin fix these same
> tissues.  I shrudder to think what these tissues are going to look like
> after I'm through thawing, fixing, processing, ect.  Any suggestions as to
> how I can do this with the minimalist damage?  Any advice as to what I
> should expect my tissue to look like after I'm through?
> 
> 
> 
> 
> Thanks a bunch!
> Margaret
> 
>

Hi Margaret,

Occasionally, because of severe freeze-thaw artifact, we have to thaw
a frozen muscle bx only to adequately re-freeze it again.  Our 
procedure usually works pretty well and hopefully will work well in 
your situation.  Here is our protocol:

1)  pre-chill saline in refrigerator
2)  semi-thaw muscle bx: when gum starts to melt around muscle then 
remove muscle and try to also remove as much gum from around the 
tissue as possible.
3)  place muscle bx into the saline at 4 degrees C for 30 minutes.
4)  blot specimen  and then submit it for paraffin processing.

I hope this helps-good luck!

Michele Margiotta
Immunohistochemistry Supervisor
UH @ Stony Brook, NY  11794