Engineers in California may have found a way to detect malaria in blood samples using a basic magnet and a laser, according to research published in the journal ACS Sensors.

The device itself is essentially a box that contains a laser and a magnet. To work, the laser points through a blood sample in a clear tube, and the device measures how much light is transmitted. Then, a magnet is held near the blood sample while a second measurement is taken.

“Healthy blood is non-magnetic,” Andrea Armani, Irani Professor of Engineering and Materials Science at the University of Southern California, told NPR. “So if you take a healthy blood sample, you put a magnet next to it, your signal isn't going to change.”

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But if the blood sample contains malaria parasites, there will be more light transmitted.

Malaria parasites produce magnetic crystals within infected red blood cells, so infected cells will move toward the magnet and be pulled out of the laser’s beam, meaning more light will shine through the tube.

Armani became interested in rapid detection tests for malaria after attending a talk in Geneva at the World Health Organization (WHO). The speakers said that better and quicker tests could play a vital role in controlling malaria.

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So Armani and her graduate student, Samantha McBirney, starting working on the device they now hope will change the way malaria impacts the world.

“[Our main goal was] keeping it as stripped and inexpensive and as easy to use as possible," McBirney told NPR.

They have not yet found a commercial partner — as a low-cost option, it isn’t very attractive to investors — but a device like this could really change how the world responds to malaria, which killed 445,000 people in 2016.

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