Nancy,
I would suggest that you try Mayer's Hematoxylin instead of the current one
that you use for H&E's.  Precipitation of hematoxylin is a normal reaction
especially when linked to alum and filtration may solve the problem for only
a short period of time.  Hope that this helps.

Susie Smith
Research Associate
Cytologix Corporation

-----Original Message-----
From: Nancy Maronto [mailto:nmaronto@hotmail.com]
Sent: Thursday, April 19, 2001 5:59 PM
To: histonet@pathology.swmed.edu
Subject: hematoxylin precipitate


Hi Everyone,
We have been performing BrdU staining on Dog tissue with a DAB chromogen.  
Our hematoxylin nuclear stain has been leaving some areas of the slide with 
what looks like precipitate.  We have diluted the hematoxylin to 50% and 
filtered it more than once.  We also have used different products, and we 
still get some of this dark blue precipitate.  can anyone suggest a reason?

One of the hematoxylins is the same as what we use for our regular H & E 
staining and our regular slides do not have any precipitate and turn out 
beautiful.  Thanks for your help

Nancy Maronto
MPI Research
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