I was taught that this 95% helps differentiate the eosin, plus eosin is
soluble in both water and alcohol, so finding eosin in first 95% is the
usual thing.  When you end up with a lot of eosin in your last 100%
alcohol, watch out, this indicates a lot of water carry over along with the
dye. You don't end up with everything overly red, a common problem.
  If you want to see how to work with this theory, Richard Allan has H&E
protocols varying eosin counterstaining and alcohol concentrations. 

You should change clarifier daily (its cheap, and also water carryover
changes the concentration of active agents) plus an inadequate rinse of
hematoxylin means more of this dye carryover into clarifier, hence a yellow
color.  Change it!   Rinsing is very important to adjust pH before eosin
staining, don't short change these important steps or H&E's can look pretty
funky.  

At 11:21 AM 10/11/01 -0500, you wrote:
>Thanks to those of you who gave a H&E rotation schedule.  I have enough
info to 
>develop a schedule for the lab.  I have a couple of more questions.  The 95% 
>alcohol following the eosin always turns pink after the first run.  Is
this OK 
>to continue staining slides with, and does this have any effect on the
quality 
>of the stain?  Also, the clarifier turns yellow after a few runs what effect 
>does this have?  Thanks 
>
>Bob Meyer, HTL 
>Northwestern University 
>
>
>
>
Gayle Callis
MT,HT,HTL(ASCP)
Histopathology Supervisor
Veterinary Molecular Biology - Marsh Lab
Montana State University - Bozeman
19th and Lincoln St
Bozeman MT 59717-3610

406 994-6367
406 994-4303 (FAX)