In a twist on traditional smart-phone accessories, researchers have demonstrated fluorescent microscopy using a physical attachment to an ordinary cell phone. The contraptiona tube-like extension hooked onto the cell phone with a modified belt clipworks just like a traditional microscope, using a series of lenses that magnify blood or spit samples on a microscope slide. To detect TB, for example, a spit sample is infused with an inexpensive dye called auramine. The cell phone approach is very valuable for all parts of the world where [medical] resources are scarce, says Aydogan Ozcan, an assistant professor of electrical engineering at UCLA, who is working to develop a lens-free method for mobile cell imaging. You need a dark room, a mercury lamp, and a lot of training.