Sounds to me like something precipitating out in solvents!
Salts of some kind such as your blueing solution?
Or perhaps if you use buffers they could be left behind?

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----- Original Message -----
From: <WWmn916@aol.com>
To: <Histonet@pathology.swmed.edu>
Sent: Tuesday, May 08, 2001 10:08 AM
Subject: Cornflaking


> Greetings,
>      I asked the very same question about one month ago.  We are
experiencing
> this artifact in a variety of ways:  ie. special stains (Congo Red,
Giemsa,
> Fx Muscle stains, Iron stains....decals turn almost a chalky white, and
some
> ipox.)  There are times I can actually see "it" develop and spread before
> having to remove and redo the coverslip.  Indeed, every now and then I
have
> to recoverslip some slides 2-3 times!  I received advice/suggestions
ranging
> from not enough xylene on the slides as they run through the coverslipper,
> trapped air, to loading only one rack of slides at a time with xylene
> dripping from them.  We are now going to try putting a little dessicant in
> our dehydrating stations.  Interestingly, a salesrep for a cover film said
> that it seems California is where this phenomenum is happening the most.
> Recoverslipping can cause a real time crunch at the most inopportune
times!
> And recoverslipping 2-3 times for the same slide makes me scratch my head!
I
> don't recall this kind of problem popping up quite like this and I would
love
> some real answers. Good luck.....and I hope to read more responses myself.
>
> Deb King
> Sacramento, CA
>