Sections (5 µm) of normal human oral mucosal tissue were deparaffinized, subjected to antigen retrieval, washed with Tris-buffered saline Tween-20 (TBST), blocked using 1% BSA, and then incubated with His6-tagged rhAMP-18 (+) or vehicle (−) overnight at 4°C. Then sections were rinsed with TBST, blocked with 0.25% soluble casein, and incubated with a rabbit anti-His antibody (top panels) or a rabbit anti-rhAMP-18 (bottom panels) for 1 hr at room temperature. The sections were rinsed, and Cy2 donkey anti-rabbit IgG was used to localize the AMP-18 ligand-receptor complex (green color). Images obtained with a Fluoview 200 laser scanning confocal microscope (60X) localize rhAMP-18 along the plasma membranes of keratinocytes (right panels). No signal was detected in tissue sections incubated in the absence of rhAMP-18 (left panels).