RESUMO
<p><b>OBJECTIVE</b>To develop a standardized IS6110-restriction fragment length polymorphism (RFLP) method, used for evaluating the capacity of genotyping.</p><p><b>METHODS</b>IS6110-RFLP of 78 Mycobacterium (M.) tuberculosis strains were studied by bio-molecular techniques including DNA isolation, PCR, restriction endonuclease enzyme analysis, southern blotting, agarose gel electrophoresis, together with data analysis by software Gel-Pro analyzer 3.1 and BioNumerics (Version 5.0).</p><p><b>RESULTS</b>IS6110-RFLP method was established and standardized successfully, including DNA isolation, PCR, restriction endonuclease enzyme analysis, southern blotting, agarose gel electrophoresis and usage of the analysis software with standard parameters. By this method, 78 M. tuberculosis isolates were classified into 75 genotypes which belonged to 11 different clusters. Of all the isolates, 66.7% (52/78) belonged to a main cluster.</p><p><b>CONCLUSION</b>Standard IS6110-RFLP method was established successfully. This method had powerful capacity for genotyping and strain level identification and could be used for the surveillance on pathogens of M. tuberculosis in China.</p>