부패 시신의 신원확인을 위한 DNA 분석 조직의 비교 및 검증: 발톱 부위별 조직과 늑연골 조직 비교를 중심으로

Abstract

Identification of unknown dead bodies is an essential element for investigation of death cases. In particular, there are a lot of cases with corpses visually(physically) unidentifiable due to decomposition, thus several different kinds of methods are being used for identification of decomposed dead bodies. However, tissues such as femurs, bone fragments, and teeth, which decay more slowly than other tissues, have to undergo a pre-treatment process, which delays the identification. In this study, the DNA concentration, degradation index, and detection frequency of DNA profiles were compared in the toenail tissues (nail-root, nail-bed, and nail-free-edge) and the costal cartilage tissues of 12 decomposed corpses requested for autopsy from January to June 2021. The weight of the tissue used for DNA purification was 0.05 g ~ 0.33 g. After DNA extraction and quantification, DNA was successfully extracted from all the tissues except for one toenail tissue. Most of the DNA degradation index values of toenail tissues and costal cartilage tissues were measured to be 2 or less, and the DNA profiles showed the concordant results between the 11 nail-bed tissues and the 11 costal cartilage tissues. After autopsy of decomposed bodies, approximately 49% of the tissues requested for identification require pre-treatment process, which leads to take a lot of time for DNA analysis. Here we have confirmed the possibility of replacing those tissues with nail-bed tissues that does not require a pre-treatment process. Furthermore, if toenail tissues, which can be easily collected compared to costal cartilages, are used, it will be useful for identification of decomposed bodies from death cases that are not autopsied.