We describe a simple method of processing rat nasal cavities for histo
logical and immunohistologic examination in which a commercial product
, HistoChoice, replaced formalin as the fixative. The nose was section
ed prior to decalcification, and ethylenediamine tetraacetic acid was
used as the decalcifying agent. The entire processing period from coll
ection of the specimen to slide preparation was less than 3 work days.
Immunohistochemical procedures to measure cell proliferation and cyto
chrome P450 activity were applied to these specimens using capillary g
ap technology.