Workpackage 4 is being conducted in parallel to Workpackage 3. Diagnosis of pulmonary TB usually requires the laboratory analysis of sputum. As a diagnostic sample matrix, sputum can be difficult to collect and analyse by microbiological and molecular techniques. WP 3 explores the potential use of other samples that are easy to obtain, such as oral mucosa samples, and how methods to preserve the DNA in transit could make transport easier. The main aim of this work package is to assess the utility of detecting the presence of M. tuberculosis in the oral mucosa of patients with TB, and to evaluate the DNA stability in different transport media.