The molecular typing for isolates in liquid media from tuberculous patients in Xinjiang by PCR.

To develope a molecular typing method for Mycobacterium tuberculosis based on the polymerase chain reaction, outward-directed PCR primers were designed to the ends of the insertion sequence IS6110.In an attempt to amplify DNA between clusters of this element on the genome, this assay utilized sequences in IS6110, which occurs as repeated copies in the chromosomes of most M.tuberculosis isolates and produce numerous bands Constituting a fingerprint. 31 strains cultured in liquid media from patients in Xinjiang. showed that IS6110-direct PCR was highly discriminatory and reproducible.6 distinct PCR fingerprinting types were found in these 31 strains. PCR fingerprinting was obtained in less than 8h, this assay does not requires subculturing, DNA purification, restriction digestion, Southern blotting, or nucleic-acid hybridization, rapid and precise identification of M.tuberculosis is possible and permits for molecular epidemiologic studies.