Microscopic observation of Mycobacterium tuberculosis in sputum smears is still the mainstay of tuberculosis diagnosis in resource-poor countries. 1 In a systematic review Karen Steingart and co-workers 2 reported that fluorescence microscopy of auramine-stained smears gave a similar specificity and on average a 10% higher sensitivity than Ziehl-Neelsen staining in 18 studies analysed, with a higher sensitivity in 16 of the 18 studies. Additionally, microscopic examination of auramine O-stained smears ...