Smartphone Scans DNA Molecules Thinner Than a Human Hair

Researchers at the University of California, Los Angeles (UCLA) have developed a device that can turn any smartphone into a DNA-scanning fluorescent microscope.

“A single DNA molecule, once stretched, is about two nanometers in width,” said Aydogan Ozcan, HHMI Chancellor Professor, UCLA. “For perspective, that makes DNA about 50,000 times thinner than a human hair. Currently, imaging single DNA molecules requires bulky, expensive optical microscopy tools, which are mostly confined to advanced laboratory settings. In comparison, the components for my device are significantly less expensive.”

Enter Ozcan’s smartphone attachment — an external lens, thin-film interference filter, miniature dovetail stage mount for making fine alignments, and a laser diode, all enclosed in a small, 3D-printed case and integrated to act just like a fluorescence microscope.

Although other smart-phone-turned-microscopes can image larger scale objects such as cells, Ozcan’s group’s latest mobile-phone optical attachment is claimed to be the first to image and size the slim strand of a single DNA molecule.

The device is intended for use in remote laboratory settings to diagnose various types of cancers and nervous system disorders, such as Alzheimer’s, as well as detect drug resistance in infectious diseases.

To use the camera it is necessary to first isolate and label the desired DNA with fluorescent tags. Ozcan says such laboratory procedures are possible even in remote locations and resource-limited settings.

To scan the DNA, the group developed a computational interface and Windows smart application running on the same smart phone. The scanned information is then sent to a remote server in Ozcan’s laboratory, which measures the length of the DNA molecules. Assuming you have a reliable data connection, the entire data processing takes less than 10 seconds.