Objective      To establish a rapid detection method of single base mutations in rifampin-resistant Mycobacterium tuberculosis by rolling circle amplification (RCA).       Methods      We used rpoB gene of rifampin-resistant Mycobacterium tuberculosis as the research target. Padlock probes were designed. The sensitivity and specificity of this method were evaluated by detecting mutation template

wild-type template

non-Mycobacteria tuberculous gene sequence template and different proportion of wild-type and mutation template mixed samples. The reaction conditions of RCA were optimized. The clinical values of the RCA method was evaluated by detecting the clinical samples and comparing the detection result with that of sequencing.       Results      RCA was used to detect the single base mutations of rpoB gene of rifampin-resistant Mycobacterium tuberculosis specifically. We proved that RCA method could detect 1% mutation template in different proportions of mixed wild-type and mutation template samples. The detection results of clinical samples were consistent with those of the sequencing.       Conclusion      There are many advantages of RCA

such as high specificity

high sensitivity

no special expensive instruments and simple operation. RCA is rapid in detection of single base mutations in rifampin-resistant Mycobacterium tuberculosis.