Abstract
Restriction-fragment-length polymorphism, analysis was used to study two outbreaks of pulmonary tuberculosis, one in a family and one in a hospital. The DNA probe was derived from the insertion sequence IS 6110. Two groups of isolates were analyzed, both of which were suspected to be common sources of each infection. Both groups showed identical fingerprints within each group. These results suggest that analysis of restriction-fragment-length polymorphism is useful in epidemiological studies of pulmonary tuberculosis.