Researchers developing smartphone-based microscope for low-cost DNA sequencing

By Heather Mack
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Researchers at California NanoSystems Institute at UCLA, Stockholm University and Uppsala University are working on a smartphone-based microscope in hopes of developing a cost-effective and accessible way for DNA sequencing and genetic mutation analysis.

As described in a recently published article in the journal Nature Communications, the researchers used a 3D printer to produce a lightweight optical attachment that can be used with any standard smartphone camera. It can capture multi-color fluorescence and bright-field images at the same quality of those created by a traditional light microscope, and can analyze specific DNA sequences and genetic mutations in tumor cells and tissue samples without the need to first extract DNA from the samples.

After placing a tissue sample in a small container, healthcare workers can use the mobile phone microscope to record multi-mode images of the processed sample, which are then algorithmically analyzed to give a sequenced DNA reading. This can show extracted tumor’s sequenced DNA bases or the genetic mutations directly inside the tumor tissue.

“It’s very important to have these molecular testing approaches at a doctor’s office or where care is being given,” Mats Nilsson, a professor of biochemistry and biophysics at Stockholm and Uppsala Universities and one of the leaders of the project, said in a statement. “Oftentimes, advanced lab-based testing is performed at major hospitals, which is limiting, as not everyone has access to a hospital that can perform these tests.”

The idea behind the project is to get the smartphone microscopes in the hands of healthcare workers who are operating with limited resources, such as in developing countries or underdeveloped communities. In these places, healthcare workers may not have access to the tools or expertise to conduct DNA sequencing analysis. With the smartphone microscope, they can detect even small amounts of cancer cells among a large group of normal cells, the researchers say.

“Ultra–low-cost DNA sequencing and tumor biopsy analysis, in which morphology and mutation analysis are combined, can substantially decrease diagnostic costs and make it more widely accessible,” Malte Kühnemund, one of the study’s first authors, said in a statement to UCLA.

If the smartphone microscope is produced in large quantities, it could cost less than $500 per device, the researchers estimate, which is far less than the $10,000 for a typical microscope with multiple imaging modes, or $50,000 for the higher-end version that the researchers used to validate their mobile phone microscope.

In addition to identifying cancer cells, the researchers also suggest the platform could eventually be used to identify disease-causing bacteria and microorganisms or measure genetic signatures of antibiotic resistance.

“The impact of this approach goes beyond molecular pathology. Other important applications may include for example, infectious disease diagnostics, where pathogen identity and load, as well as antibiotic resistance markers, can potentially be measured using the same mobile platform,” they write in the study. “With a simple DNA sequencing library preparation scheme and the capability to image NGS reactions, mobile-phone-enabled imaging and sensing tools may soon be used for targeted DNA sequencing in clinical settings and POC offices, with the potential to dramatically decrease the cost of NGS-based diagnostics globally.”

The research is being led by Nilsson and Aydogan Ozcan, UCLA’s Chancellor’s Professor of Electrical Engineering and Bioengineering and an associate director of the California NanoSystems Institute, and is supported by the National Science Foundation, the Office of Naval Research, the Army Research Office, the Howard Hughes Medical Institute, the Swedish Research Council, the Swedish Cancer Foundation, SciLifeLab and OncoTrack, which is a project of Europe’s Innovative Medicines Initiative.

Ozcan has been working on smartphone microscopy since 2009 when he founded Microskia, which was later known as Holomic and is now known as Cellmic.