DNA identification of human remains is often necessary in missing person cases or when decedents are unidentified owing to severe decomposition and skeletonization. Although current DNA extraction and analysis practices are often successful, instances of polymerase chain reaction (PCR) inhibition are frequently encountered, especially from buried skeletal remains. In the research presented, the utility of soil DNA isolation kits in skeletal DNA analysis was evaluated and compared to standard skeletal DNA extraction techniques. Mitochondrial (mtDNA) and nuclear DNA yields from buried bovine femora were compared among extraction methods and across lengths of burial. The ability of each technique to remove PCR inhibitors associated with buried skeletal remains (i.e., calcium chloride, collagen, humic acid) was also evaluated. Finally, the extraction methods were tested on ancient and modern human skeletal remains, and mtDNA haplogroup markers and a portion of the control region were sequenced. Soil DNA isolation kits were successfully used to extract skeletal DNA at quantities similar to standard extraction methods, and calcium chloride and humic acid did not result in PCR inhibition when using the soil DNA isolation kits, whereas collagen sometimes did. Concordant control region sequences were obtained from modern skeletal remains among soil kits and standard extraction methods, although extracts of ancient skeletal remains did not consistently produce concordant haplotypes. Based on the above comparisons, soil DNA isolation kits were determined to be a viable extraction technique for skeletal remains that resulted in positive identification of a decedent while quickening the extraction process.
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