Abstract The expediency of using molecular biological methods for the evaluation of M. tuberculosis
clinical strains by individual genetic certification of circulating M. tuberculosis strains has
been substantiated. Considerable genetic heterogeneity of M. tuberculosis strains isolated from
patients in different regions of the Russian Federation has been established; this heterogeneity
is due to the presence of differences in the number of copies (5-26) of element IS6110 in
M. tuberculosis cells.