Characterization of mtDNA SNP typing and mixture ratio assessment with simultaneous real-time PCR quantification of both allelic states.

We performed a study on the forensic utility of allele-discriminatory quantitative real-time PCR (rtPCR) using Minor Groove Binder TaqMan probes, targeting the highly variable mitochondrial single nucleotide polymorphism 16519T/C. The apparent single-cycle PCR efficiency was virtually 100% for both 16519 alleles. The allele designations made by rtPCR were concordant with the results obtained in a previous study by sequencing analysis. In heteroplasmic samples, minor allele proportions down to 9% were unambiguously detected and quantified. The variation in allele proportion estimates was essentially the same within and between different rtPCR runs, and the differences between total copy number estimates found for rerun samples were comparable to those found with non-allele-discriminatory quantitative rtPCR assays.