Immunohistochemistry analysis of DLL1 in immersion fixed paraffin-embedded sections of human breast cancer tissue using D2727-75 (1.7ug/ml) for 1 hour at RT followed by incubation with the Mouse IgG (HRP) Polymer Antibody. Before incubation with the primary antibody, tissue was subjected to heat-induced epitope retrieval using Antigen Retrieval Reagent-Basic. Tissue was stained using DAB (brown) and counterstained with hematoxylin (blue). Specific staining was localized to cytoplasm in cancer cells.