Diluting hematoxylin solutions with water makes the staining solution very
unstable, changes the chemical formula, ppt is the result. It  can only be
used for a few days, maybe less. Good test for anyone interested it take a
few mls of your hematoxylin solution, drop into water, let it stand, and
blue ppts show up by next morning! 

We dilute Richard Allan Hematoxylin 1, (a hemalum solution as is Gill,
Mayers, many others)  1:1 with MilQ water, and use if for one day, two at
the most.  After that, it looked pretty cruddy and ability to stain had
diminished.  We were able to dilute, not filter and stain for a day without
any ppt forming, after that, look out! Filtering diluted hematoxylin didn't
help, as the staining was poor. Our diluted stain provided a clean, very
delicate stain of nuclee, but diluted stain was tossed after a day of use. 

Can also try Gill 1 with very short staining time, a few dips followed by a
good water rinse (you will need to determine staining timing), warm water
will blue the sections very nicely. 

At 09:17 AM 4/23/01 -0400, you wrote:
>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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>
>
Gayle Callis
Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
Bozeman MT 59717-3610

406 994-6367
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