DOCK3 in Human Brain. DOCK3 was detected in immersion fixed paraffin-embedded sections of human Alzheimer's brain (cortex) using Sheep Anti-Human DOCK3 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF7134) at 3 µg/mL overnight at 4 °C. Tissue was stained using the Anti-Sheep HRP-DAB Cell & Tissue Staining Kit (brown; Catalog # CTS019 ) and counterstained with hemotoxylin (blue). Specific staining was localized to neurofibrillary tangles. View our protocol for Chromogenic IHC Staining of Paraffin-embedded Tissue Sections .