Does anybody have experience using CD54 on frozen mouse tissues (spleen, liver, lung)?  The antibody that we used is from Pharmingen cat. #553250 clone 3e2.  There's lots of background non-specific staining but, still some specific staining.  It appears to be the primary because without the primary and just secondary there's no staining.  Any help would be appreciated. 

Anne Undersander HT(ASCP)
Vet. Med./Animal Science
University of Minnesota