Analysis of an ancestry using cremated old human remains from the Korean War victims

Abstract

Analysis of DNA from burnt bone fragment is the very hard work for the human identification in forensic casework. In general, cremated bone with an artificial damage is more difficult to get an intact DNA than a singed one because of the chemical and biological drastic changes such as protein denaturation and destruction. In this study, we pursue the best technical approach for the minimal damage and the contamination of DNA from other factors in the preconditioning and the extraction process based on over 70 years old Korean War victim skeletal that was burnt and buried in Korean Peninsula. First of all, we removed the pollutant and the dust from the burnt bones using dental instruments, and then incubated with EDTA buffer at 25 ℃ to remove inhibitors such as calcium and mineral. In order to compare the DNA preservation ability between a pellet and a supernatant, samples are repeatedly tested to collect washed EDTA buffer several times to separate. Each of isolated materials is secondly cleaned with the organic extraction method using phenol and analyzed mtDNA sequence with the in-house method for the ancestry assay. The better discrimination ability was appeared in the supernatant than the pellet. Nevertheless, many of the forensic geneticists use a powdering method for getting more DNA, we applied EDTA buffer in the preconditioning step to eliminate every contamination. As a result, the contamination factor was efficiently removed and the ancestry was estimated as per the written information. Consequently, cremated bone is identified to belong in the D4 mtDNA haplogroup which is commonly reported in ethnic groups in Asia especially Korea. This is a preliminary study of a human identification over an ancestry analysis to give information against a mass disaster in a future. Through a higher process optimization and better analytical methods toward more remains, which are genetically difficult to analyze, will support to examine the identity of the post cremated remains.