A small, simple, and cheap microscope which was produced with a 3D printer and is connected to a smartphone camera can be used to analyse samples of tumours or bacteria, virus and fungal cells. The microscope and smartphone can show how the DNA chains in the sample look like, and if the doctors detect certain variants, they know exactly what form of cancer, bacteria or virus is involved. This type of examination is called DNA sequencing, which is key to discovering the most effective treatment.

– I am used to big, expensive and complicated machines which fill a whole room to do the DNA sequencing. To me, the idea to use a smartphone for this was very interesting. This opens the way to many new and very important fields of application, says Mats Nilsson from Stockholm and Uppsala University and SciLifeLab in Stockholm.

Today, advanced, lab-based testing is performed at major hospitals. The little 3D-printed microscope can make this technology accessible for many more people, even in poorer parts of the world. If the new device were produced in large quantities, it could be manufactured for much less than $500. It could run on the smartphone battery, independent from constant power supply.

 ­– Antibiotics are effective against bacteria. But now we are losing that weapon when bacteria become resistant. When it comes to tuberculosis, antibiotic resistance is a big problem. However, if we could look at the DNA-level and find out if a bacterium is sensitive to a certain type of antibiotics, we could choose the right treatment from the very beginning. This is where I think this concept has its great strength, says Mats Nilsson.

In a new study published by Nature Communications, the technique was used to identify cancerous tumours in the colon. By analysing certain mutations in the tumour, doctors could rule out the ineffective treatments, and it would also become possible to send images and information about DNA to a doctor located in a different part of the world. Researchers also hope that the technology can facilitate the diagnosis of viral infections like Ebola or Zika virus.

The microscope is the result of collaboration between researchers from the California NanoSystems Institute at UCLA, who have developed the microscope, and researchers from Stockholm and Uppsala University and SciLifeLab in Stockholm, who have worked with the analysis of the DNA chains.