In forensic investigations, mitochondrial DNA (mtDNA) is used to obtain genetic information from forensic samples. The great abundance and stability of mtDNA facilitate the successful investigation of limited quantity of samples obtained from crime scenes. Hypervariable regions 1 and 2 (HV1/ HV2) of the displacement loop are usually examined for mtDNA analysis.
Apart from DNA sequencing, the analysis can also be done by immobilized sequence-specific oligonucleotide probes, DGGE, SSCP, microarray, and mass spectrometry. However, some limitations of these methods would influence the accuracy of the results. DHPLC has recently been used to screen the HV1 and HV2 regions of the mtDNA displacement loop. The screening method is used to separate mixtures of DNA molecules obtained from body fluid mixtures. The target regions of mtDNA from DNA mixtures are amplified by PCR.
Under the partially denaturing HPLC conditions, the homo- and hetero-duplexes are evaluated, and hence the mtDNA species from forensic sample mixtures are resolved and separated. DHPLC provides a rapid, accurate and cost-effective platform for forensic investigations.