Abstract: Objective To establish DNA IS6110 fingerprinting patterns of M.tuberculosis strains and to explore distributing characters of the M.tuberculosis of Guangdong province in the molecular epidemiology.Methods The standardize method of M.tuberculosis DNA fingerprinting that is recommended by Van Embden was used for establishing the standard M.tuberculosis strains of Mt14323 and the DNA IS6110 fingerprinting patterns of seventy-four clinical isolates from Guangdong province.The data of fingerprinting patterns we detected were compared with the fingerprinting patterns data of the world by internet. The software of Gel compar 4.1(Applied Maths, Kortrijk, Belgium) were applied to analyze to the fingerprinting patterns of the strains in clustering.Results The DNA IS6110 fingerprinting patterns of Mt14323 standard strains and seventy-four clinical isolates are the same with the reports in the other country. Among 74 clinical isolates, the similar value of DNA IS6110 fingerprinting patterns of 24.3%(18/74) was form 1 to 0.65. And the result of identification showed that all of them are belong to Beijing family. It is more the isolates which have 1 copy and 2 copy (21/74).Conclusion At present, the M.tuberculosis strains of Beijing family has been prevailing in the area of Guangdong province in a certain level.

Key words: M.tuberculosis, DNA fingerprinting technology, clustering analysis