On Sat, 28 Apr 2001 TCahak@aol.com wrote:

> bx's.  We SOMETIMES experience what our pathologists call "popcorn nuclei."  
> It looks like a bubble within the nuclei and stains lighter making it very 
> distracting to look at ...

Might your artifact be from overly rapid treatment of the mounted
sections rather than of the specimens before embedding? From your
description this could this be an artifact described by G. A. Nedzel 
in 1951 (Quart. J. Microsc. Sci. 92: 343-346)? This was a residual
granule of paraffin, not dissolved out when sections were
de-waxed. Apparently it takes longer to get the wax out of
nuclei than out of the other parts of sections. It's a long 
time since I read this paper, but I remember that Nedzel said
it was more likely to occur if xylene was followed by acetone
instead of the more usual alcohol. I can't recall the remedy, but 
it must have been something pretty simple like melting the wax on 
the slides immediately before going into the first xylene, and
perhaps longer times in xylene before going into alcohol.

If your intranuclear pale inclusions are paraffin, they should be
stainable with a Sudan dye applied in the usual way, but at a
higher than usual temperature to allow the dye to dissolve in
the droplets of wax.

Just a few thoughts, and not necessarily the right one! Please keep 
us all informed, especially when you find the cause of the trouble.

Regarding rapid processing of specimens I've got a few more comments,
(which would make this reply far too long, not just too long which
it already is). I'll therefore post them to Histonet as a separate
message entitled "Rapid processing." 
 
----------------------------------------
John A. Kiernan
Department of Anatomy & Cell Biology
The University of Western Ontario
London,  Canada   N6A 5C1
   kiernan@uwo.ca
   http://publish.uwo.ca/~jkiernan