[Histonet] RE: storage of frozen cryosections (again)

[C.M. van der Loos]

   Hi Anna,

   I fully agree with John's opinion with respect to drying of
   cyrosections. I would like to add that we found out that storage at
   -20C leads to a loss of specific antigens like CD4, CD3, CD25. Storage
   of the cryosections at -80C gives a much better preservation. Even
   after many years, those "vulnerable" antigens can be detected without
   any problem.

   Chris van der Loos, PhD
   Dept. of Pathology
   Academical Medical Center M2-230
   Meibergdreef 9
   NL-1105 AZ Amsterdam
   The Netherlands

   phone:  +31 20 5665631
   fax:    +31 20 6960389
   e-mail: [1]c.m.vanderloos <@t> amc.uva.nl



   ----- Original Message -----
      From  "Anna Elisse Beaudin" <aep10 <@t> cornell.edu>
      Date  Wed, 2 Feb 2005 10:53:54 -0500 (EST)
        To  Histonet <@t> lists.utsouthwestern.edu
   Subject  [Histonet] storage of frozen cryosections (again)

   Dear Histonet,
      I have a question regarding the storage and preservation of frozen
   cryosections.  I apologize if I have asked this question before, but
   I'm still unclear as to the best approach.  Currently, when I collect
   cryosections, I dry them overnight at room temp and than use them
   immediately the next day.  however, I would like to be able to collect
   sections to use at later timepoints.  My concern is that O/N drying at
   room temperature followed by freezing and storage at -20 or -80 might
   cause  ice  crystals or otherwise affect the quality and morphology of
   my
   sections.  Additionally, even if I were to freeze the sections
   immediately  following  sectioning, they are still collected on slides
   at
   room temperature, and thus I wonder if I would have the same problem
   with thaw/freeze.  I would greatly appreciate anyone's advice with
   this... I would really like to be ! able to p

   ----- Original Message -----
      From  John Kiernan <jkiernan <@t> uwo.ca>
      Date  Wed, 02 Feb 2005 11:29:47 -0500
        To  Anna Elisse Beaudin <aep10 <@t> cornell.edu>
        Cc  Histonet <@t> lists.utsouthwestern.edu
   Subject  Re: [Histonet] storage of frozen cryosections (again)

   If you put the slides in the freezer after the sections
   have dried, there shouldn't be enough water in the tissue
   to form visible ice crystals. It's important to wrap the the
   slides up in something airtight, and with some dessicant
   (drierite or silica gel). Don't unwrap the packet until its
   contents have warmed to room temperature, or water will
   condense on the cold sections - quite damaging if the
   tissue is unfixed.
   --
   -------------------------------
   John A. Kiernan
   Department of Anatomy and Cell Biology
   The University of Western Ontario
   London,   Canada   N6A 5C1

References

   1. mailto:c.m.vanderloos <@t> amc.uva.nl