Abstract: Objective Using rDNA probe detecting mycobacteria to establish a new method detecting clinical specimen.Methods Using special primer b to produce PCR probe labeled with biotin.Specificity and sensitivity of the probe detecting primer b PCR products were studied,the positive rate of this probe detecting clinical specimen were also studied.Results The sensitivity was 100pg/μl,only M.tuberculosis and M.gastri were positive hybridization.The probe hybridized with prime b PCR products of 90 sputum specimen of pulmonary tuberculosis patients,positive rate was 80.2%.Conclusion rDNA probe with PCR was a practical Methods in detecting M.tuberculosis.

Key words: rDNA probe, M.tuberculosis, PCR