Detection and differentiation of C. hominis from C. andersoni (a) and C. hominis from C. ubiquitum (b) by RFLP analysis (SspI restriction enzyme digestion) of nested PCR products. Nested PCR-RFLP analysis was carried out in 5 replicates for plasmid templates mixed at 1:1 ratios (10 copies each). (a) Nested PCR-RFLP products in lanes 1, 2, and 5 contain a mixture of amplified products from C. hominis and C. andersoni, whereas only C. andersoni and C. hominis were amplified in lanes 3 and 4, respectively. (b) Nested PCR-RFLP products in lanes 1, 2, and 4 contain a mixture of amplified products from C. hominis and C. ubiquitum, whereas only C. hominis and C. ubiquitum were amplified in lanes 3 and 5, respectively. The arrow indicates undigested PCR products.