Abstract: Objective To evaluate the clinical valu of liquid-based Peng’s interlayer vessel technique on detecting acid-fast bacilli (AFB). Methods 642 morning sputum specimens and 1140 timely sputum specimens were collected from 1190 patients with suspected pulmonary tuberculosis, each sputum specimen was detected simultaneously by three Methods as follow: liquid-based Peng’s interlayer vessel technique, sputum smear and acid-fast staining microscopy (direct AFB) and Lwenstein-Jensen (L-J) culture. Result Of 642 morning sputum specimens, the positive rates of Peng’s interlayer vessel technique, direct AFB and L-J culture were 23.5%, 12.7%, 26.6%, respectively. Of 1140 timely sputum specimens, their positive rates were 18.1%, 9.6% and 23.3%, respectively. The positive rate of morning sputa was significantly higher than that of timely sputa (P<0.05). Using L-J culture as golden standard, the sensitivity and specificity of Peng’s interlayer vessel technique were 68.9% and 95.8%, respectively, which were significantly higher than those of direct AFB (P<0.05).  Conclusion The liquid-based Peng’s interlayer vessel technique could increase the sensitity of sputum detecting and had higher specificity. It was simple, convenient, easy to be standardized, andworthy to popularize as a diagnostic method of pulmonary TB.

Key words: tuberculosis, pulmonary/ diagnosis, Mycobacterium tuberculosis, bacteriological techniques