Collagen XIII a1 in Human Placenta. Collagen XIII a1 was detected in immersion fixed paraffin-embedded sections of human placenta using Mouse Anti-Human Collagen XIII a1 Monoclonal Antibody (Catalog # MAB6346) at 15 µg/mL overnight at 4 °C. Tissue was stained using the Anti-Mouse HRP-DAB Cell & Tissue Staining Kit (brown; Catalog # CTS002 ) and counterstained with hematoxylin (blue). Specific staining was localized to basement membrane. View our protocol for Chromogenic IHC Staining of Paraffin-embedded Tissue Sections .