Figure 2. Immunohistochemistry of the porcine secretory-stage enamel showing immunolocalization of enamel proteins using light microscopy (Uchida et al., 1991b). The four antibodies used (from left to right) were a polyclonal antibody raised against intact (25 kDa) amelogenin, an anti-peptide antibody specific for the amelogenin C-terminus, polyclonal antibodies raised against 13- to 17-kDa ameloblastin cleavage products, and polyclonal antibodies raised against the 89-kDa enamelin. The amelogenin C-terminal antibody, indicative of the intact protein, was restricted to the surface enamel. The ameloblastin antibody produced a honeycomb pattern over the entire thickness of the immature enamel. The enamelin antibody generated a reverse honeycomb pattern. Key: secretory ameloblasts (Am), immature enamel (E), dentin (D), Golgi (arrowheads). Approximate magnification, 520x.