Could a new form of medical testing for developing countries be found far from any laboratory -- in a dehydrated, wallet-sized, disposable Mylar card?
These prototype cards, recently described in the journal Lab on a Chip, are part of a long-term project funded by The Bill and Melinda Gates Foundation's Grand Challenges in Global Health Initiative. The point is to develop “affordable, easy-to-use diagnostic tools for the developing world” that “use features of common lab tests and take into account portability, automation and easy storage.”
In order for this technology to work, the tests must be storable for long periods of time at ambient temperatures. They plan to use the astronaut-food approach, where the reagents are dried down to successfully store them without refrigeration. This is key for physicians diagnosing patients in poor countries around the world because many lab tests contain ingredients that must be kept cold, but often no refrigeration is available.
This test must also be developed to be fast and easy to use, since health care workers might only have one visit to diagnose and treat a patient. In these cases, they do not have time to wait days for lab results. While the prototype developed only tests for malaria, cards of the future will hopefully also test for other high-fever diseases like dengue, influenza, typhoid, and measles.
This card is part of a system hoping to diagnose malaria away from a lab. The red circle at the center contains dehydrated antibodies that can be stored for months without refrigeration. The tiny channels guide a blood sample through the card to the white rectangle. Upon getting there, a red spot will appear, and its intensity shows whether the patient is infected.
Click to read more about this project.