Application comparison of three TB DNA extraction methods from stool samples of patients with pulmonary tuberculosis

Objective To Compare three DNA extraction methods including boiling lysis method,phenol/chloroform method,and kit method for TB DNA detection in stool specimens of patients with pulmonary tuberculosis.Methods Stool specimens of pulmonary tuberculosis patients are collected and treated separately with boiling lysis method,phenol/chloroform method and kit method.TB DNA positive detection rates and amplification efficiency of these three methods were analyzed and compared with real time PCR.Results TB DNA amplification was no detected in stool specimens of sputum smear negative patients.The TB DNA detection rates of these three methods were 45%,70% and 80%,respectively.The quantitative result of TB DNA in the kid method group was significantly higher than that in the phenol/chloroform method group.Conclusion Compared with the other two methods,kit method can more effectively remove PCR inhibitors which has a high diagnosis value for pulmonary tuberculosis patients,who can not produce or cough up sputum.