Fig. 2A. : detection limit for semi-nested polymerase chain reaction (PCR). Line 1: molecular weight marker of 100 bp; 2-9: 10-fold dilution curve, 1 ng-0.1 fg; 10: negative control; B: detection limit for internal PCR. 1: molecular marker (Low DNA Ladder); 2-8: 10-fold dilution curve, 100 pg-0.1 fg; 9: negative control; C: specificity of internal PCR. 1: molecular weight marker of 100 bp; 2: genomic DNA of Schistosoma mansoni; 3: genomic DNA of Trypanosoma cruzi; 4: genomic DNA of Leishmania chagasi; 5: genomic DNA of Ascaris lumbricoides; 6: genomic DNA of Homo sapiens; 7: genomic DNA of Wuchereria bancrofti; 8: negative control.