Microscopes are invaluable tools to identify blood and other cells when screening for diseases like anemia, tuberculosis and malaria. But they are also bulky and expensive. Now an engineer, using software that he developed and about $10 worth of off-the-shelf hardware, has adapted cell phones to substitute for microscopes. 'We convert cell phones into devices that diagnose diseases,' said Aydogan Ozcan, an assistant professor of electrical engineering and member of the California NanoSystems Institute at the University of California, Los Angeles, who created the devices. He has formed a company, Microskia, to commercialize the technology. The adapted phones may be used for screening in places far from hospitals, technicians or diagnostic laboratories, Ozcan said. In one prototype, a slide holding a finger prick of blood can be inserted over the phone's camera sensor. The sensor detects the slide's contents and sends the information wirelessly to a hospital or regional health center. For instance, the phones can detect the asymmetric shape of diseased blood cells or other abnormal cells, or note an increase of white blood cells, a sign of infection, he said. Ozcan's devices provide a simple solution to a complex problem, said Ahmet Yildiz, an assistant professor of physics and molecular cell biology at the University of California, Berkeley. 'This is an inexpensive way to eliminate a microscope and sample biological images with a basic cell phone camera instead,' he said. 'If you are in a place where getting to a microscope or medical facility is not straightforward, this is a really smart solution.' Neven Karlovac, the chief executive of Microskia in Los Angeles, said that some of the company's products would be adaptations of regular cell phones. For phones without cameras, or phones too compact to modify, the company has different designs, including a simple box with a sensing chip that can be plugged into a cell phone or laptop with a USB cord, he said. 'The idea is to commercialize this low-cost cell imaging and diagnostic platform and apply it to a number of different products,' Karlovac said. The price of the devices has not been set. Ozcan's devices are compact in part because they have eliminated the central element in a microscope -- its lenses -- said David J. Brady, a professor of electrical and computer engineering at Duke University and director of its Imaging and Spectroscopy Program. 'There's no need for lenses in these devices because the magnification can be done electronically,' he said. 'You don't need optics at all.' For this electronic system of magnification, inexpensive light-emitting diodes added to the basic cell phone shine their light on a sample slide placed over the phone's camera chip. Some of the light waves hit the cells suspended in the sample, scattering off the cells and interfering with the other light waves. 'When the waves interfere,' Brady said, 'they create a pattern called a hologram.' The detector in the camera records that hologram or interference pattern as a series of pixels. The holograms are rich in information. 'We can learn a lot in seconds,' Ozcan said. 'We can process the information mathematically and reconstruct images like those you would see with a microscope.' Ozcan's system may someday lead to a rapid way to process blood and other samples, said Bahram Jalali, an applied physicist and professor of electrical engineering at UCLA. 'It is potentially much faster than a microscope,' he said. 'You don't have to scan mechanically' as people must with a microscope with its small field of view. 'Instead you capture holograms of all the cells on the slide digitally at the same time,' he said, so that it's possible, for example, to see immediately the pathogens among a vast population of healthy cells. 'It's a way of looking quickly for a needle in a haystack,' he said. The cell phone systems may be particularly helpful in screening for malaria, said Yvonne Bryson, a professor and chief of the pediatric infectious diseases division at the David Geffen School of Medicine at UCLA. She has collaborated with Ozcan on several grants. 'Right now you need a microscope, and you need trained people,' Bryson said. 'But this device would allow you to work without either in a remote area.' M. Fatih Yanik, an assistant professor of electrical engineering and computer science at the Massachusetts Institute of Technology, said, 'This makes it possible for ordinary people to gather medical information in the field just by using a cell phone adapted with cheap parts.' 