We are staining paraffin embedded liver sections for desmin using either
peroxidase or FITC/TxRed.  For some unknown reason, we get beautiful staining
using peroxidase, but not with the fluorescent secondary (either FITC or TxRed).
We know that the primary AB is working as expected.  We can do both the
peroxidase and fluorescent staining in frozen sections and both work great.
When we try to do the same in paraffin embedded sections, the peroxidase works
fine, but the fluroescent staining is undetectable (even when we only dilute the
secondary AB 1:10).  Can anyone suggest a solution to this problem or even what
the problem could be?

Thanks in advance for your help.


Susan Garfield
Laboratory of Experimental Carcinogenesis
Division of Basic Sciences
National Cancer Institute, NIH
Building 37, Room 3C28
37 Convent Drive MSC4255
Bethesda, MD  20892-4255
Phone: 301-496-5688; Fax: 301-496-0734