Abstract: Objective To develop a new method for detecting smear-negative sputum from patients with pulmonary tuberculosis,for the objectives of rapidly detection and determine viable bacillus.Methods By using a new method,called bacteria proliferation accompanied PCR(BPAP),which combine culture with Middlebrook 7H12 semi-liquid media and PCR,46 specimens were detected.Their Southern-blot Results were analyzed by Gel-Pro Analyzer software.Results (1)For smear-negative specimens,to the 7th day,the sensitivity of BPAP was 86.2%;To 4 weeks,BPAP reached its highest sensitivity.It needed a shorter time to the detection of M.tuberculosis for BPAB than culture(P<0.01);And it had a higher sensitivity for BPAP than common PCR(P<0.05).(2)Out of 46 specimens ,there were 29 specimens(63.0%)that Southern-blot IOD ratio between the 7th day and the Oth day>1 zero;And for those specimens got their positive BPAP Results within 7 days,62.1% were supported by the positive 7H12 semi-liquid cultuer results.Conclusion BPAP is not common PCR.Through 7 days’ bacteria proliferation,there is a significant increase in the sensitivity.And for the support and determination of viable organisms by culture and Southern-blot IOD ratio.BPAP helps to get a more accurate clinical diagnosis.

Key words: Tuberculosis,pulmonary, PCR