Abstract: Objective To assess the performance of fluorescence microscopy with light emitting diodes (LEDFM) in detectingMycobacterium tuberculosis . Methods Using solid L-J culture (L-J) as gold standard, 409 sputum samples were detected by Ziehl-Neelsen (ZN), conventional fluorescence microscopy (FM) and LEDFM. Their sensitivities, specificities, detection times, and feeling of the user were compared. Results Of 175 L-J-positive samples,112 samples were ZN positive,121 samples were FM positive,130 samples were LEDFM positive. Their sensitivities were 64.0%, 69.1%, 74.3%, respectively. Of 234 L-J-negative samples, 233 samples were ZN negative, 227 samples were FM negative, 227 samples were LEDFM negative. Their specificities were 99.6%，97.0%，97.0%, respectively. There were significant difference among the Results of LEDFM and the other two Methods （P<0.001). Detection times of ZN-, FM-, LEDFM-positive slides were 186.7 sec, 75.1 sec, 72.2 sec, respectively, in which there was significant difference between ZN and LEDFM（P<0.05），but not between FM and LEDFM. LEDFM was highly appreciated by technicians involved in this study.  Conclusions LEDFM had better efficacy and use value in detectingM tuberculosisthan ZN and FM.

Key words: Mycobacterium tuberculosis, microscopy, fluorescence