Quick and cheap MIRU-VNTR typing of Mycobacterium tuberculosis species complex using duplex PCR

While minisatellites are usually typed using capillary sequencers or qiaplex systems in developed countries, many low-resource regions cannot afford it. We propose an optimized agarose gel electrophoresis method to genotype Mycobacterium tuberculosis species complex minisatellites in their standardized format (24 MIRU-VNTR). It is based on duplex PCRs combining VNTR loci harboring distinct amplicon sizes whatever the repetition number of each locus. This method performs well both on DNA extracts of good quality and on thermolysates while reducing workload and reagents costs.