Table 1.

Primer combinations used in this study and expected results according to the number of IS6110 copies inserted within the DR locus of M. tuberculosis

Primer setPrimeraResult with given no. of IS6110 copies
ForwardReverse1 copy2 copiesb
Ac DRbBiot-DRaAll spacers presentAll spacers present
BBiot-DRbIS3No amplificationNo amplification
CIS3Biot-DRaRight DR spacersRight and central DR spacers
DBiot-DRbIS6Left DR spacersLeft and central DR spacers
EIS6Biot-DRaNo amplificationNo amplification
  • a The directions of the forward and reverse primers are deduced from previous DR sequence data (11). Biot, biotinylated.

  • b If the two copies of IS6110 are inserted in the same direction.

  • c Positive control.