Researchers at the University of California, Los Angeles (UCLA) have built a cheap 3D-printed attachment able to turn smartphones into sophisticated microscopes. Armed with the new device, a smartphone would be able to detect single DNA strands and analyze them to diagnose diseases including cancer and Alzheimer’s without bulky and expensive equipment.

Cheap and portable medical diagnostics could make a real difference in assisting patients in third-world countries or remote areas, and microscopes are an important part of the arsenal. In the past, we've seen several attachments that can turn phones into microscopes for a measly price.

The device designed by Professor Aydogan Ozcan and team, however, pushes the envelope further than ever before by giving smartphones the ability to scan single strands of DNA, a mere two nanometers across.

The tool is designed to act just like a fluorescent microscope, which works by labeling the samples with fluorescent molecules and then "exciting" them with a laser. These types of microscopes can detect drug resistance in infectious diseases as well as imaging DNA to diagnose cancer and Alzheimer’s disease. But, because they are very bulky and expensive, these tools are only available in specialized labs.

The researchers squeezed a fluorescent microscope down to a practical size (Image: UCLA)

Ozkan and team managed to pack an external lens, a thin-film filter, a miniature dovetail stage mount and a laser diode inside a small 3D-printed case to make their own miniature fluorescent microscope. A software interface running on the smartphone scans the DNA and sends the data to a remote server in the team’s laboratory. The servers use the data to measure the length of the DNA strands, and return the results in less than 10 seconds, assuming users have access to an internet connection.

The scientists tested the device’s accuracy by imaging stretched DNA segments, showing that it can accurately size DNA strands of 10,000 base pairs or above, a range that includes many important genes. The microscope was less reliable for strands below 5,000 pairs, but this could be remedied with relative ease simply by replacing the external lens.

Next up, Ozcan’s group plans to test their microscope in the field to detect the presence of malaria-related drug resistance.

An open-access article describing the advance appears in the journal ACS Nano (PDF).

Source: UCLA via The Optical Society