In-Solution Hybridization for the Targeted Enrichment of the Whole Mitochondrial Genome

A detailed protocol is presented for the targeted enrichment of whole mitochondrial genomes based on an in-solution hybridization strategy. Bait is produced in-house by sonication of two long-range PCR amplicons and ligation of biotinylated double-stranded adapters. Indexed target DNA is hybridized with the bait in a multiplex enrichment reaction and pulled down using magnetic streptavidin beads followed by subsequent post-enrichment PCR and sequencing on an Illumina MiSeq. This strategy removes the need for expensive commercial bait probes while allowing enrichment of multiple samples in a single hybridization reaction. The method is particularly suitable for degraded DNA as it is able to enrich short DNA fragments and is not susceptible to polymerase artifacts introduced during PCR-based assays.