Slot reference mix, signifying the starting point of electrophoresis

Lane 1 RFLP control strain (Mt 14323) from the Netherlands Lanes 2-22: DNA fingerprints from several M. tuberculosis strains (samples from the last two wells are from the same patient)

Fig. 2 Representative RFLP profiles of M. tuberculosis using IS6110 as a probe.

patterns are detected by placing a light-sensitive film on the wrapped membrane in a light-blocked cassette[8] (Fig. 2). Restriction fragment length polymorphism has been used to confirm outbreaks of tuberculosis or incidents of suspected laboratory cross contamination,1-9-1 to investigate the question of reinfection vs. reactivation, to examine the existence of multiple infections, and to track the spread of multidrug resistance.1-10-1 DNA fingerprints of M. tuberculosis do not change during the development of resistance to various antituberculous drugs.[11] However, there are a number of notable limitations with standard IS6110 typing. For example, it is labor intensive and thus costly. The typing patterns produced have varying numbers of bands which may also vary in position, so that sophisticated software is needed to analyze large numbers of patterns and to compare results between laboratories.1-12-1 Furthermore, RFLP typing of strains with a low copy number of IS6110 is not sufficiently discriminatory.1-6,13,14-1 Additional genetic typing method in cases where M. tuberculosis isolates contain fewer than five IS6110 copies is necessary.

In addition to IS6110, many other different DNA sequences that have been used as probes for typing M. tuberculosis complex strain by RFLP include the major polymorphic tandem repeat (MPTR), the polymorphic GC-rich sequence, the direct repeat region, (GTG)5, repetitive DNA elements, and rDNA (ribotyping).[6,15,16]

Was this article helpful?

0 0
Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

Get My Free Ebook

Post a comment