The device uses a drop of saliva or blood placed on blotter paper that has cells embedded in its matrix. RNA in the cells on the paper have been programmed to react with specific Ebola strains, and dots on the paper turn from yellow to purple when Ebola is present.
Unfortunately, the device is not quite ready to use in Africa, where the current Ebola epidemic is raging. Scientists need to make the device more sensitive so it can detect smaller quantities of Ebola before it can have widespread use.
http://www.msn.com/en-us/news/technology/new-pocket-sized-blotter-test-can-detect-ebola-strains-in-just-30-minutes/ar-BBbIbe0