FIG. 4.

Two models of sequential use of the three typing methods used to analyze the 158 M. tuberculosis strains. (A) Spoligotyping is the first-step test; (B) LMPCR is the screening method. In both cases IS6110 RFLP analysis is considered the most discriminatory test, following double-step typing by the PCR-based methods. For each step, the black and white bars on the left represent the fraction of clustered isolates and the fraction of isolates with unique patterns, respectively, while the percentages of clustered strains are shown on the right.