固相萃取-GC/NPD检测血中毒鼠强

毒鼠强检血稀释后加入401树脂吸附,滤集树脂于小层析柱中,用二氯甲烷洗脱,洗脱液挥干加入内标物,用GC/NPD法检测毒鼠强的含量.     

陈旧骨骼DNA提取及性别鉴定

用本室建立的方法对3～15年的陈旧骨骼进行DNA提取，并用X、Y同源引物扩增AInelogenin基因X、Y特异性片段，所有检材均得出正确结论，表明该方法快速、灵敏、可靠，适用于陈旧骨骼性别鉴定。     

血中毒鼠强的固相萃取和GC-NPD法测定

目的 研究人全血中毒鼠强的固相革取(SPE)。方法 用Bond Elute C18固相萃取柱萃取,GC-NPD检测,以甲基对硫磷为色谱内标(CS)。结果 全血中加标0.5μg/ml,毒鼠强回收率为92.5％,变异系数2.3％(CV,n=4)。在0.5～10μg/ml的浓度范围内,线性相关系数为0.9994。检出限(S/N=3)和定量限(S/N=10)分别为6ng/ml和20ng/ml。同一根萃取柱连续使用6次未见性能明显下降(CV=3.6%)。结论 本文方法适用于毒鼠强中毒的全血测定。     

Forensic human identification: Investigation into tooth morphotype and DNA extraction methods from teeth

When a body is decomposed, hard tissues such as teeth may provide the only DNA source for human identification. There is currently no consensus as to the best DNA extraction method, and there is a lack of empirical data regarding tooth morphotype and condition that may impact DNA recovery. Therefore, this study sought to investigate which variables significantly improved DNA concentration, integrity and profiling success. A total of 52 human teeth were assessed, representing all tooth morphotypes from three deceased individuals. DNA was extracted using both the QIAamp® DNA Investigator Kit and the phenol-chloroform method. DNA concentration and degradation index were assessed using real time PCR, prior to conventional DNA profiling. Contrary to international guidelines promoting the use of molars, DNA profiling from molars was the least successful, with premolars, followed by canines, performing the best. The presence of fillings reduced the DNA quantity and quality obtained and may explain the poor performance of molars. DNA from the maxillae were significantly less degraded when the QIAamp® was used, although this did not influence DNA profiling success. A significant increase in DNA concentration, integrity and profiling success was observed in diseased teeth (periodontitis) compared to those without disease. This may be due to increased white blood cell presence at the site. There was no significant difference in DNA profiling success between the two DNA extraction methods. However, different teeth yielded failed DNA profiles for each extraction method, suggesting that repeated attempts, using alternative DNA extraction methods, is recommended. The recovery of additional DNA profiling information from degraded samples may help to ultimately reduce the burden of unidentified human remains.     

An investigation of two methods of DNA recovery from fired and unfired 9 mm ammunition

Cartridge cases are often recovered from crime scenes involving firearms and, in the United Kingdom (where gun possession is strictly controlled), these are commonly from 9 mm calibre ammunition. The ability to obtain informative DNA profiles from touch DNA on recovered cartridges could have a significant impact on the investigation of that type of offence. However, this avenue may not be routinely considered as investigators in the UK have historically had a low expectation of obtaining useful DNA profiles. This stance may not be unreasonable given that (a) only trace amounts of DNA are likely to have been transferred onto the cartridge cases through handling; and (b) when the cartridge is spent, the potential deterioration of that DNA caused by the act of discharging the weapon.We introduce a novel semi-automatable method using direct lysis for the recovery of DNA from ammunition and compare it with a traditional double-swabbing method (using wet and dry swabs). DNA profiling of the DNA recovered using both methods was carried out using the ESI17 FAST STR system (Promega). This demonstrated a significant increase in DNA recovery using the direct lysis approach, and correspondingly improved STR results.We also investigated the effect on the recovery and profiling of DNA from fired, and unfired, 9 mm cartridges using the direct lysis technique. These results demonstrate that DNA suitable for STR analysis can still be recovered from fired ammunition with only slightly reduced yields compared to unfired ammunition. In these experiments, the handler of the ammunition was most commonly either the sole contributor or the major contributor to the recovered DNA profile.     

定量转印技术确定圆珠笔字迹的相对书写时间

定量转印技术是将单溶剂提取法与转印技术相结合形成的方法,实验表明该方法在一定条件下可以判定圆珠笔字迹的相对书写时间.     

樗白皮提取物对小白鼠体内黄嘌呤氧化酶活性的影响

为了研究樗白皮提取物对小白鼠机体内黄嘌呤氧化酶(XOD)活性的影响,将实验动物分为5、10、30 g/kg樗白皮提取物灌喂组和正常对照组,对各组动物血清、脾、肝中XOD活性进行了测定。结果,10 g/kg樗白皮提取物能够降低小白鼠血清、脾、肝组织中的XOD活性,30 g/kg樗白皮提取物能提高上述各组织中的XOD活性,5 g/kg樗白皮提取物组小白鼠组织中的XOD活性接近正常对照组。结果表明,不同剂量的樗白皮提取物对小白鼠体内XOD活性的作用不同,低剂量时具有抗氧化作用,高剂量时表现为促氧化作用。     

Application of BioRobot M48 to forensic DNA extraction

The development of a nucleic acid extraction method based on magnetic separation has opened up possibilities forl automation of DNA extraction. The BioRobot M48 is one of robotic stations applicable to automated DNA extraction in forensics. However, each new method should be thoroughly validated before application to routine casework. Our aim was to compare the effectiveness of the currently utilized organic/Microcon 100 based extraction procedure and magnetic extraction with BioRobot M48. The DNA concentration of DNA extracts obtained from different kinds of typical forensic material was evaluated followed by amplification with the SGM Plus or Identifiler kit and capillary electrophoresis using ABI 3100 Avant. We can conclude that BioRobot M48 is a very effective instrument for DNA extraction from most specimens and can be successfully applied in forensic laboratories.     

交通事故现场液体痕迹的勘查与应用

液体痕迹,是属于交通事故现场中地面痕迹的一种。通过对事故现场的液体痕迹发现、采取与对其种类、形态特征进行分析和检验,就能够为鉴别嫌疑车辆,追踪、堵截和认定肇事逃逸车辆,提供的证据。     

常见季铵盐类农药分析检测方法研究进展

本文概述了近几年来季铵盐类农药的提取净化及检测方法的研究进展,比较了固相萃取法、液液萃取法、超临界流体萃取等前处理技术的优劣,重点介绍了液相色谱及其液质联用技术在该领域的应用情况。