Kita Toshiro, Yamaguchi Hiroki, Yokoyama Mitsuru, Tanaka Toshiko, Tanaka Noriyuki
Department of Forensic Medicine, School of Medicine, University of Occupational and Environmental Health Yahata Nishi-ku, Kitakyushu, 807-8555 Japan.
Forensic Sci Int Genet. 2008 Dec;3(1):32-6. doi: 10.1016/j.fsigen.2008.09.002. Epub 2008 Oct 11.
In recent years, forensic scientists showed that an individual's genetic profile can be retrieved from touched objects. Degraded DNA is believed to originate from epidermal cells and to be responsible for this phenomenon, yet the mechanism has not been confirmed. In the present study, we carried out a morphological and immunohistochemical investigation of nuclear DNA in differentiating keratinocytes in the skin and also a genetic analysis of DNA on swabs of human skin. Immunoelectron microscope analysis showed that single-stranded DNA was found both in the cornified layer of the skin and in swabs. Real-time-PCR assay proved that the DNA in the swabs was derived from the human DNA. Electron microscopic analysis of shadow-cast showed the presence of small DNA fragments in the swabs. It is conceivable that these DNA fragments on touched objects may originate from the epidermal cells of the cornified layer that are constantly sloughed off and leave for skin surface with sweat.
近年来，法医科学家表明，可以从触摸过的物体中获取个体的基因图谱。降解的DNA被认为起源于表皮细胞并导致了这种现象，但其机制尚未得到证实。在本研究中，我们对皮肤中分化的角质形成细胞中的核DNA进行了形态学和免疫组织化学研究，并对人体皮肤拭子上的DNA进行了基因分析。免疫电子显微镜分析表明，在皮肤角质层和拭子中均发现了单链DNA。实时荧光定量PCR检测证明拭子上的DNA来源于人类DNA。阴影投射电子显微镜分析显示拭子中存在小的DNA片段。可以想象，这些触摸物体上的DNA片段可能来自角质层的表皮细胞，这些细胞不断脱落并随汗液留在皮肤表面。
