Application of solid-state capture for the retrieval of small-to-medium sized target loci from ancient DNA

Genetic studies that include ancient samples are often hampered by the low amount of endogenous DNA that ancient samples often contain, relative to co-extracted “contaminant” DNA from other organisms. One approach to mitigate this challenge is to perform hybridization-based capture of target genomic regions using DNA or RNA baits. Such baits are designed to have high sequence similarity to the target genomic regions and can reduce the off-target fraction in DNA sequencing libraries. Here, we present a protocol to use Agilent SureSelect microarrays to enrich ancient DNA libraries for small-to-medium-sized target loci, such as mitochondrial genomes, from ancient DNA extracts. The protocol that we present builds on previously published work by introducing improvements that improve recovery of short DNA fragments while minimizing the cost and duration of the experiment.