Immunohistochemistry analysis of CDA in paraffin-embedded human intestinal cancer tissue. Antigen retrieval was performed on the tissue using citrate buffer (pH 6, 20 min) and blocked with 10% goat serum. Samples were incubated with CDA polyclonal antibody (Product # PA5-95616) at a 1 µg/mL dilution, followed by biotinylated goat anti-rabbit IgG (30 min, 37°C), and developed with Strepavidin-Biotin-Complex and DAB.