Transmission Electron Micrograph (TEM) of two epithelial cells with microvilli, joined by a junctional complex. Two epithelial cells are joined when their lateral cell membranes fuse, forming a belt-like structure known as a junctional complex. Further down the lateral border there is an electron dense region just inside each cell. This is a place where the two cells are attached (but not fused) and is known as a desmosome. The surface of these two cells is formed into microvilli, many of which have been cut in cross-section and appear as fuzzy circles in the top of the micrograph. Magnification: 20,000x @ 8 x10 inches.