Age determination of blood spots in forensic medicine by force spectroscopy
Age determination of blood spots in forensic medicine by force spectroscopy
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DOI：
10.1016/j.forsciint.2006.08.023
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发表时间：
2007-07-20
影响因子：
2.2
通讯作者：
Thalhammer, Stefan
中科院分区：
文献类型：
--
作者：
Strasser, Stefan;Zink, Albert;Thalhammer, Stefan
我们提出了一种新的工具，估计的年龄的血迹，这可能会被用于法医案件。为此，我们使用原子力显微镜（AFM）对血液样品中的红细胞进行高分辨率成像，并检测纳米尺度上的弹性变化。对于分析程序，我们在载玻片上施加新鲜血点，并在血滴干燥后开始AFM检测。在第一步中，生成显示几个红细胞的存在的概览图像，由于它们典型的"甜甜圈状"外观，可以容易地检测到这些红细胞。在4周的时间范围内进行的连续形态学研究未显示任何变化。其次，利用原子力显微镜（AFM）记录力-距离曲线，测试其弹性。在干燥后立即、1.5小时、30小时和31天进行测量。条件保持恒定在室温（20 ° C）和30%的湿度。将获得的弹性参数相对于时间轴作图并重复数次。弹性模式显示出随时间的推移而降低，这很可能是受干燥和凝固过程中血斑变化的影响。初步数据表明，该方法的能力，使用它的校准曲线的发展，可用于估计血迹的年龄在法医调查。(C)2006爱思唯尔爱尔兰有限公司保留所有权利。
We present a new tool for the estimation of the age of bloodstains, which could probably be used during forensic casework. For this, we used atomic force microscopy (AFM) for high-resolution imaging of erythrocytes in a blood sample and the detection of elasticity changes on a nanometer scale. For the analytic procedure we applied a fresh blood spot on a glass slide and started the AFM detection after drying of the blood drop. In a first step, an overview image was generated showing the presence of several red blood cells, which could easily be detected due to their typical "doughnut-like" appearance. The consecutively morphological investigations in a timeframe of 4 weeks could not show any alterations. Secondly, AFM was used to test the elasticity by recording force-distance curves. The measurements were performed immediately after drying, 1.5 h, 30 h and 31 days. The conditions were kept constant at room temperature (20 degrees C) and a humidity of 30%. The obtained elasticity parameters were plotted against a timeline and repeated several times. The elasticity pattern showed a decrease over time, which are most probably influenced by the alteration of the blood spot during the drying and coagulation process. The preliminary data demonstrates the capacity of this method to use it for development of calibration curves; which can be used for estimation of bloodstain ages during forensic investigations. (C) 2006 Elsevier Ireland Ltd. All rights reserved.