Objective        To establish a quick

sensitive

specific and quantitative method for detecting aspergillus for clinical diagnosis of aspergillosis.       Methods        Aspergillus fumigates

Aspergillus flavus and Aspergillus niger were cultured

and the spores were harvested. The total RNA was extracted from the spores. Ten-fold serially titrated Aspergillus conidia (101 to 106 spores) were detected by nucleic acid sequence-based amplification (NASBA) and molecular beacon (MB) platform to establish a standard curve. The sensitivity and specificity of the method were evaluated.       Results        The reaction time (minute) of the fluorescence signal rising above the fixed threshold was linearly correlated with the logarithm of the spore amount (y=-10.7x+81.6

r=0.988). The detection limit of this method was 1 spore. The RNA extracted from aspergillus and the comparisons (Staphylococcus aureus

Escherichia coli

Pseudomonas aeruginosa

Candida albicans

Candida tropicalis and Cryptococcus neoformans) were amplified by NASBA

and were analyzed by electrophoresis. NASBA did not cross-react with the non-target bacteria or fungi.       Conclusion        The method of NASBA combined with MB has high sensitivity and specificity

and can be potentially used for medical diagnosis of aspergillosis.