UCLA engineers create a smartphone-based fluorescence microscope

smartphone-based fluorescence microscope

Researchers from UCLA’s California NanoSystems Institute have reported the first demonstration of imaging and measuring the size of individual DNA molecules using a lightweight device that converts an ordinary smartphone into an advanced “fluorescence microscope.”

This sort of microscope works by labeling the samples with fluorescent molecules that are “excited” with a laser. This process gives off different colored light that the microscope detects and uses to build images of fluorescently labeled samples, visualizing objects that are 100 to 1000 times smaller than the diameter of human hair.

An inexpensive, 3-D-printed optical device uses the phone’s camera to visualize and measure the length of single-molecule DNA strands.Led by Aydogan Ozcan, associate director of the UCLA California NanoSystems Institute and Chancellor’s Professor of electrical engineering and bioengineering at the UCLA Henry Samueli School of Engineering and Applied Science, the research team developed an inexpensive, 3-D-printed optical device that uses the phone’s camera to visualize and measure the length of single-molecule DNA strands. The device includes an attachment that creates a high-contrast, dark-field imaging set-up using an inexpensive external lens, thin-film interference filters, a miniature dovetail stage and a laser diode that “excites” the fluorescently labeled DNA molecules.

Working in tandem with an accompanying mobile app, the device connects the smartphone to a server at UCLA, which rapidly measures the lengths of the individual DNA molecules. The results of DNA detection and length measurement are then sent back to the mobile phone and on remote computers linked to the UCLA server.

“The ability to translate these and other existing microscopy and sensing techniques to field-portable, cost-effective and high-throughput instruments can make possible myriad new applications for point-of-care medicine and global health,” said Ozcan. He went on to say that these devices could have far-reaching positive impact on research and educational efforts in developing countries or resource-limited institutions, helping democratize advanced scientific instruments and measurement tools.

These devices could have far-reaching positive impact on research and educational efforts in developing countries or resource-limited institutions.Compared to this “smartphone solution,” regular fluorescent microscopes are expensive, bulky and relatively complicated, typically making them available only in high-tech laboratories.

This project was funded by an EAGER Award from the National Science Foundation (NSF). Ozcan’s lab is also funded by the Presidential Early Career Award for Scientists and Engineers, Army Research Office (ARO), ARO Life Sciences Division, NSF CAREER Award, NSF CBET Division Biophotonics Program, NSF Emerging Frontiers in Research and Innovation Award, Office of Naval Research, and the Howard Hughes Medical Institute.