Abstract: Objective To develop a method for extracting lipoarabinomanan（LAM）fromMycobacterium tuberculosis , and to evaluate serodiagnosis value of LAM for pulmonary tuberculosis.   Methods Mycobacterium tuberculosiswas sonicated in ice and then refluxed with ethanol; treated with DNase I and RNase; removed proteins with phenol; removed phenol and lipide with chloroform/methanol. The crude lipopolysaccharide (LPS) was prepared. LPS was purified with Sephacryl-100 gel filtration, and LAM were obtained. LAM was used as antigen to detect anti-LAM IgG in serum by dot immunogold filtration assay.  Results The relative molecular weight of LAM was approximately 37 kDa, consistent with the reference. The sensitivity, specificity, positive predictive value, negative predictive value and coincidence with smear were 91.7%, 87.8%, 92.7%, 86.2% and 90.2%, respectively.  Conclusions LAM was obtained successfully. LAM used as antigen to detect anti-TB antibody in serum showed good specificity and sensitivity, and might be one of canditate antigens for the serodiagnosis of TB serology.

Key words: Tuberculosis, pulmonary/diagnosis, Mycobacterium tuberculosis, lipopolysaccharides