Richard,

For many years our protocol has been to place the frozen OCT block directly
into ambient temperature NBF. Thawing occurs in the fixative, agitation is
neccesary as the OCT liquifies. When compared to tissues allowed to thaw
prior to fixation, this technique appeared superior.
There is still freeze/thaw damage but the paraffin sections are acceptable.

Bryan

Bryan R. Hewlett
Technical Specialist
Anatomical Pathology
Hamilton Regional Laboratory Medicine Program
Ontario, Canada

----- Original Message -----
From: "Richard Cartun" 
To: 
Sent: Friday, June 21, 2002 2:33 PM
Subject: Thawing frozen tissue for H&E


> We received 3 biopsies of colon to R/O Hirschsprung's disease.
> Unfortunately, all of the tissue was frozen in O.C.T. so we have nothing
> for permanent sections.  What is the best way to thaw the frozen tissue
> before submitting it for H&E?  Should we trim away the excess O.C.T. and
> place it in formalin or should we "wash" it in tissue culture media
> (RPMI) before placing it in formalin?  Obviously, preservation of
> morphology is critical here.  Thanks!
>
> R. Cartun
>
>