I have recently worked up the DAKO antibody to mast cell tryptase on canine
tissue and get strong positive staining of normal mast cells and mast cell
tumors.  However, there is also this strange nuclear staining that is
present in the nuclei of epithelial cells, much like that type of nuclear
staining seen when using anti-PCNA.  Has anyone else (in Human IHC Land)
observed this phenomenon, or is it just me (and/or my dogs)?

I use the standard automated IHC protocol for tryptase (Proteinase K enzyme
pretreatment for 5 minutes; primary antibody at 1:50 for 30 minutes; DAKO
LSAB2 kit; ready-to-use AEC chromogen-substrate).

Jan Shivers - Scientist
Univ. of Minn. Veterinary Diagnostic Lab
1333 Gortner Ave.
St. Paul, MN  55108
shive--3@tc.umn.edu
612-624-7297