Hi Ray,
    Currently we don't keep the patient blocks in the refridgerator but I
have been giving it some serious thought lately; for a subgroup of cases
(not enough space given our volume!).  Although I have never done a formal
study for the loss of antigenicity by antibody, I have noticed a significant
loss in breast stained for ER and PR when trying to find new controls using
old patient cases. I will pull old known positive slides that are 4+ at
initial staining and when the ER and PR are tested again, they tend to
decrease to 2+ and in some cases even more.  These are the only two that I
have noticed a problem with and so I am looking into the feasibility of
storing those blocks in the fridge.

    Has anyone else noticed this type of decrease with those antibodies?

Cheryl

> ----------
> From: 	KoellingR@immunex.com[SMTP:KoellingR@immunex.com]
> Sent: 	Thursday, April 05, 2001 3:22 PM
> To: 	George, Cheryl
> Cc: 	histonet@pathology.swmed.edu; 'Michelle Peiffer'
> Subject: 	RE: storing controls
> 
> Cheryl,
> Do you keep test (or patient blocks) in refrigerator?  Just curious about
> your thoughts regarding having a control  block/section nicely positive
> for
> "X" from the refrigerator stained next to a test section/block for "X"
> that
> has been stored at room temp and is negative.  Would it truly be so?
> 
> Thanks,
> Ray
> Seattle, WA
> 
> 
>  
> 
>                     "George,
> 
>                     Cheryl"               To:
> histonet@pathology.swmed.edu, 'Michelle      
>                     <CGerorge@Elli        Peiffer' <mlk101@psu.edu>
> 
>                     ot-HS.org>            cc:
> 
>                                           Subject:     RE: storing
> controls                    
>                     04/05/01 09:36
> 
>                     AM
> 
>  
> 
>  
> 
> 
> 
> 
> Michelle,
> 
> We store all of our control blocks and slides in the refridgerator.
> 
> Cheryl
> 
> > ----------
> > From:         Michelle Peiffer[SMTP:mlk101@psu.edu]
> > Sent:         Thursday, April 05, 2001 10:28 AM
> > To:           histonet@pathology.swmed.edu
> > Subject:           storing controls
> >
> > Thanks to all who responded about my IHC decreased staining post.
> >
> > Several people have mentioned storage of the controls.  Some are
> purchased
> > slides, so obviously they are precut and they are stored in the
> > refrigerator.  But most are freshly cut from blocks which are stored at
> > room temperature.  I was under the impression most people store blocks
> at
> > room temperature, is this correct?  How long can controls last?  We just
> > started doing histology so our oldest blocks are only 6 months old.
> >
> >
> > Michelle
> >
> >
> > Michelle Peiffer
> > *************************************************************
> > Electron Microscope Facility for the Life Sciences
> > Penn State University Biotechnology Institute
> > 001 South Frear Lab
> > University Park PA 16802
> >
> > phone: 814-865-0212
> > email:  mlk101@psu.edu
> > **************************************************************
> >
> >
> 
> 
> 
> 
>