Do it Yourself TB Test

With a cardboard box, a light source, and some filters, roadside clinics can accurately test for tuberculosis.

Sep 5, 2012
Edyta Zielinska

After solving the structure of an enzyme from the tuberculosis bacterium, researchers from Stanford University in Palo Alto created a probe that lights up when the enzyme is present, potentially reducing false negatives inherent to the current diagnostic methods. The results were published this week (September 2) in Nature Chemistry.

Mycobacterium tuberculosis, the causative agent of tuberculosis, produces and secretes the enzyme BlaC, which breaks down proteins like ß-lactams, present in many antibiotics including penicillin. Once researchers solved the enzyme's structure, they were able to design a molecule similar to ß-lactam, but which would fluoresce a bright blue glow when broken down by BlaC.

“This method is powerful because it does not rely on access to a microscope and lab facilities,” Bill Jacobs of the Howard Hughes Medical Institute and Albert Einstein College of Medicine in New York, who was not involved in the study, told Nature, nor does it require sputum samples to be cleaned or processed. “And it is much more sensitive than the other tests currently available," able to detect as few as 10 tuberculosis bacteria in a sample.