Researchers at the University of California (UC), Berkeley have developed a compact fluorescent microscope that attaches to an ordinary camera phone. The CellScope made its debut in April when the research team announced their original bright field microscope model. The latest prototype adds fluorescent microscopy capabilities.
“Fluorescence microscopy requires more equipment - such as filters and special lighting - than a standard light microscope, which makes them more expensive,” said Dan Fletcher, UC Berkeley professor of bioengineering and head of the research team. “In this paper, we’ve shown that the whole fluorescence system can be constructed on a cell phone using the existing camera and relatively inexpensive components.”
The CellScope uses compact microscope lenses attached to a holder that snaps onto a camera phone. The fluorescent microscopy model uses a light-emitting diode (LED) as the light source. Filters restrict the LED to 460 nm, the wavelength that excites the green fluorescent dye that labels the tuberculosis-causing bacterium Mycobacterium tuberculosis. The researchers have successfully captured fluorescent images of this bacterium, as well as bright-field images of sickle-shaped red blood cells and Plasmodium faceiparum, the parasite that causes malaria in humans. The images taken with a 3.2 megapixel mass-market camera phone achieved a spatial resolution of 1.2 micrometers.
The phone is designed for field use in areas with poor health care. The images recorded can be analyzed immediately or wirelessly transmitted to clinical centers for remote diagnosis.
The team is currently developing sturdier CellScope prototypes that will be used in more extensive field testingThe findings are published in “Mobile Phone Based Clinical Microscopy for Global Health Applications,” available online at PLoS ONE.