Dawn,

I have that same problem here.  It occurs on cell blocks from various labs
so it is not only an in house problem.  I tell my clients that all my
antibodies are optimized for FFPE tissue and that although they can choose
to order IHC on cell blocks, smears, autocytes, etc..., the results will not
be as good as on FFPE tissues.  I never felt comfortable contacting the
cytology departments responsible for making these blocks and dictating how
they do their work so that my work will turn out, cytotechs tend not to
appreciate that.  

Glen Dawson

-----Original Message-----
From: Julian-Boyd, Dawn [mailto:Dboyd@swmedctr.com]
Sent: Thursday, March 20, 2003 12:27 PM
To: 'histonet@pathology.swmed.edu'
Subject: Background staining IHC cell blocks


Our small private facility which does app.. 10,000 cases per year is
experiencing difficulty with an increase in background on various antibodies
with cell block preparations.

Our cytology department rinses the button in cytolyte then adds 2-3 drops of
thrombin and plasma per their protocol.  We realize the proteins are a
problem.  We would like to know if there is another protocol for the
preparation of cell blocks minus the plasma and thrombin. 

Help please!

Dawn