HIV-1 budding on a lymphocyte. Photo: CDC

It might be no big deal for you to stop into the local clinic for an HIV test. But for some countries, testing needs to be cheaper.

Researchers at the Imperial College London have discovered a way to make that happen. Molly Stevens and her team developed a test using nanoparticles that can be used without expensive equipment in almost any environment. All the tester needs to do is mix serum from the patient’s blood with a solution of gold nanoparticles. If the person has HIV, the virus’s p24 biomarker will make the gold particles bond together in a way that turns the solution blue. If p24 is not present, the solution will turn red, with the particles forming ball shapes.

Not only is the test more sensitive than current methods, its 10 times cheaper. And Stevens says the solution could be modified to test for other diseases like malaria, sepsis, tuberculosis and prostate cancer.