Solar-driven PCR used to detect cancer

New Scientist : Kaposi’s sarcoma, which is caused by a herpes virus, is the most common cancer in sub-Saharan Africa. Up to 70% of those infected die within three years, so early detection is key. The KS-Detect, built by Li Jiang and David Erickson of Cornell University, may provide doctors with that ability. The device focuses sunlight on a microscopic channel etched on a microchip. The channel is filled with a sample from a patient, and the heat from the sunlight drives a polymerase chain reaction (PCR), which amplifies the presence of DNA from the herpes virus that causes the cancer. A dye mixed into the sample glows when the DNA concentration reaches a detectable level. The chip then sends the result to an attached smartphone. Normally, PCR requires a lot of electricity, which is not readily available in much of sub-Saharan Africa. The technology may also be adaptable for other diseases, such as tuberculosis.