Tuberculosis is still a huge global health problem, with the most frightening part perhaps being the multi-drug resistant strains of the mycobacterium. One obstacle which has hampered effective control of this disease, especially in poor countries, is the long time it takes to diagnose it. In these lower-income areas, the standard diagnosis of TB is by microscopy, but this does not give any information on drug-resistance - those cell culture tests take two weeks, by which time it might have spread to many other people.
A Swiss group, The Foundation for Innovative New Diagnostics, has come up with a better way. The sputum sample is first treated with sodium hydroxide and alcohol, killing any TB, and the sample is fed into a small device which analyzes the DNA and gives a simple report regarding the presence of TB and the resistance status of the organism. This shrinks the time-frame for diagnosis of multi-drug resistant TB from 2 weeks to 2 hours. The individual tests cost only $17, although the machine costs $17,000. This is a nice example of cutting-edge technology being scaled to low-cost applications in resource-poor areas.
http://www.medgadget.com/archives/2011/01/rapid_dnabased_tuberculosis_test_has_results_in_two_hours.html
