Detection of Her2 in mouse mammary tumor tissue sections. Mammary
tumors were identified in transgenic mice expressing the human gene
encoding Her2 under the control of the mouse mammary tumor virus promoter (Sharon Erickson, personal communication). Formalin-fixed, paraffin-embedded tumors were sectioned at 5 and treated with Target Retrieval
(DAKO Corporation, Carpinteria, CA), Avidin Biotin Blocking Solution
(Vector) and 10% (vol/vol) normal goat serum plus 3% (wt/vol) BSA before
being incubated sequentially with 5 of a rabbit anti-Her2 polyclonal
antibody directed against the cytoplasmic domain of Her2 (catalog no.
A0458; DAKO Corporation) for 30 min, biotinylated goat anti-rabbit IgG
for 30 min, and finally with 40 nM QD 630–streptavidin for 30 min. Slides
were mounted with Vectashield containing DAPI (Vector).