RE: Calretinin

From:Kirbis Srebotnik Irena

RE: Calretinin

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 []
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.


----- 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 []
  Sent: Tuesday, May 13, 2003 1:16 AM
  To: Cindy DuBois; Histonet
  Subject: Re: Calretinin


  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
  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.


  Bryan Hewlett
  Ex Technical Specialist in IHC now just an old retired guy.

  ----- Original Message -----
  From: "Cindy DuBois" <>
  To: "Histonet" <>
  Sent: Monday, May 12, 2003 6:06 PM
  Subject: Calretinin

  > ----------
  > From: Cindy/Rick DuBois <>
  > Date: Wed, 7 May 2003 09:58:50 -0700 (PDT)
  > To:
  > Subject: Calretinin
  > Our docs have noticed that our Calretinin does not stain on cell blocks.
  > These specimens are initially received in cytolyte (alcohol based
  > a cell block is prepared and processed in the tissue processor with the
  > of the tissue.
  > The control we are using stains positively and is a mesothelioma from
  > lung (formalin fixed tissue).
  > Any suggestions on how to get the cell blocks to stain?  Any help would
  > greatly appreciated.
  > Cindy DuBois HT, ASCP
  > Delta Pathology Assoc.
  > Stockton, CA

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