Figure 3. Results of RFLP analysis for isolates of the Mercian strain across the Midlands between 1995 and 2003.

Each horizontal lane is an example of an individual M. tuberculosis strain from each location and year. The molecular sizes of the digested DNA fragments of MT14323 are shown in kilobases. The 8^th IS6110 fragment was identified in an isolate from Wolverhampton in 2003.