Special remarks: This antiserum is specific to Claudin-12. It does not cross react with Claudin-1, -2, -3, -4, -5, -6, -7, -8, and -15.

The tight junction is identified as a belt-like region in which two lipid-apposing membranes lie close together (tight junction strands). Tight junction strands of the adjacent cells form tightly connected pairs. The proteins involved in the formation of tight junctions are divided into two categories: 1) integral membrane proteins, such as occludin, claudin and junctional adhesion molecule, JAM and 2) peripheral membrane proteins (cytoplasmic plaque proteins), MAGUK (membrane-associated guanylate kinase) homologue proteins, such as ZO-1, 2, 3, cingulin, symplekin, 19B1, and AF-6. In human, the claudin superfamily consists of at least 18 members, which are involved on paracellular transport as structural and functional components of tight junction. Claudins are directly associated with ZO-1, 2 and 3 and indirectly with AF-6 and cingulin.