Reply to John Dennis, Ty Lee, Eric Scharf, and
others...

Thanks for all the input. 

>From the advice I've gotten, I'm leaning to the
thought that the DNA may not be sufficiently
denatured.  These tissues went through tissue
decalcification, which normally negated the need to
perform a HCL acid step during staining.  At least
that was the way our protocol was originally designed.
(We do include an enzyme digestion step with
proteinase K.)

However, I do not tightly control the tissue to volume
ratio of the formic acid solution I use for
decalcification.  Perhaps my staining variability
comes from the fact that some of the animals were not
as well decalcified as others.  I will try restaining
using the HCL step to see if things improve.

Again thanks for all the assistance recieved!!

===
Catherine "Katie" Bresee Bennett
Laboratory for Experimental Pathology
Department of Veterinary Pathology
Michigan State University

*new* e-mail: bresee98@yahoo.com

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