I use cobalt chloride on my old tissue tek to help me to determine when the 
100% ETOH stations need to be changed since I do not process daily. I have 
also used it in an enclosed processor without any problems. If you use the 
right amount you get a blue stain on the tissue that makes the embedding so 
much easier. We loved using this for small gastric biopsies because you 
could differentiate the mucosal layer without any problem - cervical 
biopsies too. If you use too much the whole tissue stains blue making it a 
little harder to see the different layers of tissue. In the dip'n dunker I 
have now I use about a half teaspoon/1000ml.
When you cut your section and float it on the waterbath the blue color goes 
away.
Andi
.....................................................................
: Andrea Grantham, HT(ASCP)     Dept. of Cell Biology & Anatomy     :
: Sr. Research Specialist       University of Arizona               :
: (office:  AHSC 4212)          P.O. Box 245044                     :
: (voice:  520-626-4415)        Tucson, AZ  85724-5044    USA       :
: (FAX:  520-626-2097)          (email:  algranth@u.arizona.edu)       :
:...................................................................:
           http://www.cba.arizona.edu/histology-lab.html