Screening the Heteroplasmy of Hypervariable Region I of Human mtDNA by DHPLC

[Objective] To examine the heteroplasmy of hypervariable region I of human mtDNA, and to establish an effective technique to screen low-level heteroplasmic DNAs. [Method] The 269 bp PCR products of the hypervariable region I of 2 kinds of mtDNAs differed from only one alkali base were mixed in different ratios as models. Heteroplasmic mtDNAs were examined by DHPLC. The optimal conditions for testing were determined. The PCR products of the Hypervariable Region I of mtDNAs from 80 individuals were examined. [Result] The least distinguishable ratio of the heteroplasmic DNAs (269 bp fragments) was 5% . 15 cases of heteroplasmic mtDNAs were found by this method in the samples tested. [Conclusion] The established method of PCR-DHPLC can be used for screening the heteroplasmy of mtDNA.