Figure 4. Agarose gel electrophoresis prepared for amplification of variable minicircle fragments of Leishmania kDNA by the nested PCR. Lane 1, DNA size marker, 100 bp; lane 2, negative control (distilled water); lane 3, L.major (positive control, 560 bp); lane 4, L.tropica (positive control,750 bp); lanes 5–7, L.tropica isolates obtained from the cutaneous leishmaniasis cases among opium addicted and opium non-addicted cohorts.