On Mon, 21 Dec 1998, Gayle Callis wrote:

> I would be curious to find out if anyone has had success doing thick
> cryosections, free floated variety or otherwise??  I tend to avoid
> anything over 10 um, and prefer a range of 4 - 7 um in order to maintain
> a flat, easy to handle section.

  Several of my colleagues routinely cut animal brains at 50-100 um
  and do all sorts of immunohistochemistry, with 24-48 hour incubations
  in primary at 4 deg C. The sections are cut with an old fashioned
  freezing microtome, not a cryostat. I've done the same with post
  mortem human brain, and also with dissected layers of rat intestinal
  wall, which must be 150-200 um thick. The antibodies seem to soak
  in all right, given time and gentle agitation on a rocker. For
  some reason, the incubations in secondary antisera, PAP etc can
  be much shorter - only an hour or so.

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1
   Phone: (519) 679-2111
   FAX (Department): (519) 661-3936
   E-mail: kiernan@uwo.ca