Population Variances in the Whole Mitochondrial Genome Impacting Capture for Human Identification

The mitochondrial genome (mtGenome) holds a wealth of information that can be used for human identification purposes. Sequencing and analyzing the entire mtGenome can help to obtain more of this information. However, library preparation steps prior to sequencing could be problematic when dealing with compromised or degraded samples. A capture/hybridization assay targeted to the entire mtGenome can enrich for the target DNA without PCR or chemically altering the DNA. The melting temperatures (Tm) of two different length fragments for an African American and Caucasian individual were mapped across the length of the genome to study any variation that might occur. While population-specific Tm differences seem to be almost negligible, there is wide intra-individual Tm variation, ranging from about 11-31°C. To overcome the issue of an assay run at a single set of temperature parameters, two separate reactions optimized for higher and lower Tm values could prove to be more efficient.