两种DNA提取法对不同色泽肋软骨STR分型成功率的比较

目的比较两种DNA提取法对不同色泽肋软骨的DNASTR分型结果的影响。方法利用Chelex-100法和酚-氯仿法,分别对30例不同色泽的腐败尸体肋软骨进行DNA提取,STR复合扩增,ABI3100型基因分析仪对扩增产物进行检测。结果用酚-氯仿法提取的30例腐败尸体肋软骨,均检测到全部STR基因座的等位基因型。用Chelex-100法提取的肋软骨中,22例(11例白色、8例淡黄色、3例黄色)检测出全部STR基因座的等位基因型;7例(3例黄色、4例黄褐色)检测出部分STR基因座的等位基因型;1例黑灰色的腐败尸体肋软骨,未检测出STR基因座的等位基因型。结论根据肋软骨的色泽,选择适宜的DNA提取方法。对于颜色较深的肋软骨,用酚-氯仿法进行DNA提取有助于提高其STR基因座的检出率。     

血尿肝中毒鼠强硅藻土提取GC／NPD检测法

目的建立硅藻土提取气相色谱测定血、尿、肝中毒鼠强的方法。方法原尿液、血液用水稀释、肝匀浆用6％高氯酸沉淀蛋白的上清液倒入硅藻土小柱中，血和尿用苯洗脱，肝用三氯甲烷洗脱，挥干洗脱液，用甲醇定容至0．1ml。结果血提取率98．4％，尿提取率95．6%，肝提取率98．1％。相对标准偏差低于3．2％，检出限低于20ng／ml（g）。结论该法简便、快速，提取率高，适合作为常规毒物分析方法。     

赤足跖后缘自动提取与自适应变模型特征识别

将经典Snake模型与自适应变模型相结合的算法，快速提取图像中的开边缘并识别边缘形状，实现赤足足迹跖后缘的自动提取与形状识别。首先，对原图像校正、平滑去噪，由数学形态学方法得到Snake模型的初始轮廓，迭代求解实现跖后缘的快速、精确提取。然后，由高次多项式进行数字滤波，再对滤波后的边缘曲线，利用先验知识，依据平均曲率的变化，自适应地选取不同的函数模型，提取出相应特征，自动识别边缘形状。该方法边缘提取准确，特征提取合理，使计算机总体识别率达到90％。     

尿中异丙嗪及其代谢物含量硅藻土萃取紫外导数光谱测定法

目的建立尿中异丙嗪原体及其代谢物异丙嗪亚砜的提取测定方法。方法取尿直接倒入硅藻土柱中，用二氯甲烷洗脱，收集洗脱液50℃水浴挥干。剩余物用3．0ml 0．05mol／L硫酸溶解。加入锌粉沸水浴加热，放冷，测定二阶导数光谱。结果异丙嗪亚砜和异丙嗪萃取率均达90％以上，线性范围0．5～5．0μg／ml。结论该方法操作简便，提取率高，重现性好，结果可靠。     

亚甲基双氧甲基苯丙胺中毒检验方法的研究

详细讨论了亚甲基双氧甲基苯丙胺中毒后生物体内的提取、净化和检验方法,得出了生物体内亚甲基双氧甲基苯丙胺的提取最佳条件,净化方法和GC/FID定量分析方法,为类似毒品中毒的体内定性定量检验提供了参考.     

GC／MS检测尿中4种苯氧羧酸类除草剂

目的建立尿中2，4-D、2，4-DP、MCPA、MCPP等4种苯氧羧酸类除草剂的分析方法；方法液液提取分离，乙醚为提取液，DCPA为内标，硫酸正丁醇酯化衍生化，气质联用分析法分析；结果尿中4种除草剂添加样品的相对回收率在80％以上，检测限都在5ng／ml以下，对中毒兔尿样进行了分析；结论对实际发生的中毒案件分析有足够的灵敏度。     

A comparison of three automated DNA purification methods in Forensic casework

Manual Chelex^®-100 and organic extractions (phenol/chloroform) are used as routine methods at the Swedish National Laboratory of Forensic Science, SKL. The aim of this study was to find an automated DNA purification system to replace the organic method. The following methods were evaluated and compared to each other and to the organic method used routinely; BioRobot^® EZ1 with EZ1 DNA Investigator Kit and Card (Qiagen), iPrep™ Purification Instrument with iPrep™ ChargeSwitch^® Forensic Kit and Card (Invitrogen), Magnatrix™ 1200 Workstation with the Magnatrix™ gDNA Blood Kit Forensic and two different protocols; Forensic protocol A and B (Magnetic Biosolutions). Blood on fats, cotton swabs, moist snuff, paper towels and leather, post-mortem blood and muscle tissue were extracted with the different methods. DNA concentration and quality of the electropherograms were examined. Individual comparisons between the four extraction methods showed that iPrep™ and Magnatrix™ 1200 gave significantly lower mean quantities compared to BioRobot^® EZ1 and the organic extraction method (p < 0.05). There were no significant differences between the latter two. BioRobot^® EZ1 generated the best results and is in the process of being validated for routine analysis at SKL.     

Examination of pretreatment methods for DNA extraction from nails

In the conventional method of DNA extraction from nails, it takes approximately half a day to dissolve the nails. In this study, we examined whether using the HOrizontal Nail MAshing (HONMA) method, in which pressure is applied to the nail to crush it flat and increase its surface area, would improve DNA extraction efficiency. Fingernails (5 mg) provided by ten volunteers were used as samples. Nail pieces (1–3 pieces), shredded with nail clippers, were thinly stretched by applying 2 t of pressure to each piece using a hydraulic press. DNA was extracted by incubation at 56 °C for 10 min and 1 h during proteolysis. DNA yield from the nails pretreated using the HONMA method increased by 0.20–7.10 times compared with that from unprocessed nails. In particular, 10-min incubation using the HONMA method resulted in an average 2.05-fold increase in DNA yield compared with that under overnight incubation. However, the impact of using the HONMA method varied widely among individuals, and the amount of extracted DNA decreased in some cases, suggesting that the yield may differ depending on the nail quality.