Barbara
The technique is after dewaxing section go to absolute alcohol. Use a solution
of  0.5-1% celloidin in alcohol:ether (1:1 v/v). Fume hood. This solution is
dripped over over the sections , allowed to get ALMOST dry and then slide
placed in 70% alcohol to harden. Do not allow to get completely dry!!
When completed staining, the celloidin can be removed with acetone before going
into absolute or xylene or can be left covering the section. To retain
celloidin go from 70% ethanol to a mixture of alcohol:chloroform (3:1 v/v).
The celloidin that you use must be real celloidin i.e. parlodion and not LVN.
Soak celloidin strips in absolute etahnol until softened and then add the
ether.

Two problems.
1.    Some stains such as celestine blue will stain the celloidin and render it
insoluble ( in anything we have tried including strong acids).
2.    Celloidin acts a a very effective barrier to penetration of enzymes so
that it will not work with some histochemical and IHC procedures.
Barry

"Greenfield, Barbara" wrote:

> A question for the gurus of Histology.
>
> Many years ago (and I emphasize many) the lab I trained in used a technique
> for post treating paraffin sections to keep them on the slide through some
> of the silver staining techniques.  It involved dipping the mounted,
> deparaffinized slides in a mixture containing celloidin.  Does this ring a
> bell out there, and if so do you remember the concoction and procedure
> details?
>
> Any pearls of wisdom would be appreciated.
>
> Barbara Greenfield
> Laboratory Operations Manager
> Erie Scientific, Co.
> 20 Post Road
> Portsmouth N.H. 03801