Just a couple of follow-up comments on my earlier post.

1) In our lab with our formulation of hematoxylin, we have obtained 
exceptional results with hematoxylin pH in the range of 1.8-2.0. This is 
lower than the acceptable range commonly reported.

2) During a period of 5 years we used a regressive technique with 0.1 % HCL 
in 70% EtOH for differentiation and ammonia water for bluing. Almost all of 
the slides from this period exhibit seriously faded nuclear staining. A 
little more than three years ago we went to a more controllable progressive 
stain with a modified Harris Hematoxylin at pH 2.0 and blue in running 
water only. These slides have not faded. Granted this is a completely 
empirical observation with no scientific control and I have no potential 
explanation for why this might have occurred.

Bert Dotson