Control of many diseases such as tuberculosis and malaria is more effective if the disease can be diagnosed quickly allowing the patient to be treated more quickly before spreading the disease by infecting others. Unfortunately, while molecular tests are increasingly used for diagnosis, they can be complicated and have to be done in a laboratory. This takes time. There is a need for more simple and rapid molecular tests that can be done near the patient – so-called ‘under a tree’ diagnosis. We have used our experience of tuberculosis to build such a near patient ‘under a tree’ test. The video shows the test for tuberculosis but other diseases can be tested too.