From: | Kirbis Srebotnik Irena |
Dear Bryan,
I totally agree with you that it is essential to use control which is processed in the same manner as the test samples. And we always use the proper positive and negative control. We are cytopathology dept. and we perform immunostainings only on cytology samples since 1989, according to our experiences fixation in methanol preserve all antigens we work with that is 42 different antigens. But I have to tell that what I'm talking about is fixation of cytospins in methanol and not cytoblocks!
If you are interested I can send you a picture of beautiful reactions we are getting on cytospins.
have a nice day
Irena Kirbis
-----Original Message-----
From: Bryan Hewlett [mailto:bhewlett@cogeco.ca]
Sent: Wednesday, May 14, 2003 2:31 AM
To: Kirbis Srebotnik Irena
Cc: Cindy DuBois; HistoNet Server
Subject: Re: Calretinin
RE: CalretininIrena,
I did not say that calretinin and the other markers could not be detected,
just that they do not respond well to the fixation.
The point is, that using an IHC protocol optimized for formaldehyde fixed
tissue on formaldehyde fixed controls and alcohol fixed cell blocks is
essentially no control at all!!
The controls should be fixed and processed in the same way as the test.
Bryan
----- Original Message -----
From: Kirbis Srebotnik Irena
To: 'Bryan Hewlett' ; Cindy DuBois ; Histonet
Sent: Tuesday, May 13, 2003 5:28 AM
Subject: RE: Calretinin
according to our experiences calretinin as well as other mentioned markers
can be detected after fixation in methanol !
Irena Kirbis
-----Original Message-----
From: Bryan Hewlett [mailto:bhewlett@cogeco.ca]
Sent: Tuesday, May 13, 2003 1:16 AM
To: Cindy DuBois; Histonet
Subject: Re: Calretinin
Cindy,
Unfortunately, your positive tissue control is not a control for your test
material! So you should disregard the results.
Tissue controls should be fixed and processed in the same manner as the
test
sample.
In our experience calretinin is one of the markers that does not respond
well to alcohol fixation.
Other markers used for the differentiation of mesothelioma vs
adenocarcinoma, e.g. CEA, EMA and the epithelial antigen (BER-EP4) also do
not like alcohol fixation. Too late now since the specimen was received in
cytolyte, but we always fixed our cytology cell blocks in NBF, so our
standard controls were appropriate. You could try to obtain some fresh
positive tissues and fix them in cytolyte, then re-optimize your IHC
protocols to the new fixation conditions. You will then have some
appropriate IHC controls for your cell blocks.
Regards,
Bryan Hewlett
Ex Technical Specialist in IHC now just an old retired guy.
----- Original Message -----
From: "Cindy DuBois" <ccdub@earthlink.net>
To: "Histonet" <histonet@pathology.swmed.edu>
Sent: Monday, May 12, 2003 6:06 PM
Subject: Calretinin
>
> ----------
> From: Cindy/Rick DuBois <ccdub@earthlink.net>
> Date: Wed, 7 May 2003 09:58:50 -0700 (PDT)
> To: ccdub@earthlink.net
> Subject: Calretinin
>
> Our docs have noticed that our Calretinin does not stain on cell blocks.
> These specimens are initially received in cytolyte (alcohol based
fixative),
> a cell block is prepared and processed in the tissue processor with the
rest
> of the tissue.
> The control we are using stains positively and is a mesothelioma from
the
> lung (formalin fixed tissue).
> Any suggestions on how to get the cell blocks to stain? Any help would
be
> greatly appreciated.
> Cindy DuBois HT, ASCP
> Delta Pathology Assoc.
> Stockton, CA
>
>
>