Dr Clare Green presents her data on the use of urine as a diagnostic target for pulmonary TB at 'The Challenge of TB: UCL's Contribution' held on 24th March 2010. She describes the small, cell free nucleic acids, known as transrenal DNA, that can be detected in urine of infected individuals. Previous studies have shown huge variability on the sensitivity of this assay of the detection of TB, and Dr Green’s work has examined factors that might influence this variation - such as the patient group, sample preparation and the assay design - in order to try to optimise this technique as a clinical tool.