微波提取山茱萸马钱素的工艺研究W

以山茱萸为原料，在微波场的作用下，进行了不同微波提取溶剂、料液比、提取时间、提取温度、提取功率和正交优化实验对山茱萸中马钱素提取率的影响研究。结果表明：影响微波提取的因素依次为提取时间、提取温度、提取功率。优选方案为：微波提取溶剂为水，料液比1∶30，提取时间10min, 提取温度70℃，提取功率300W,山茱萸马钱素提取率为0.80%。     

一种改良骨骼DNA的提取方法

采用十六烷基三甲基溴化铵(简称CTAB)及两次纯化浓缩的方法提取骨骼DNA,利用荧光标记复合扩增、自动毛细管电泳与分型的技术,成功检测到14个STR位点的分型.该方法稳定、结果可靠,为严重降解骨骼DNA的提取提供了一种可参用的方法.     

用Chelex100法及有机溶剂提取法联合提取DNA扩增STR基因座的比较研究

为了比较不同方法提取DNA扩增STR基因座的成功率 ,本文用Chelex10 0法及Chelex10 0法联合有机溶剂提取法分别提取性犯罪案件 6份血斑及 6份混合斑中精子DNA ,并用PE公司ProfilerPlus系统复合扩增 ,ABI 310型基因分型仪检测。结果表明 ,常规采用Chelex10 0法提取血斑及精斑等生物检材DNA作STR基因座检验失败或所检测的位点较少时 ,应对Chelex10 0法提取的DNA上清液再用有机溶剂提取法提取 ,可极大提高DNA检验成功率。采用本文建立的Chelex10 0法联合有机溶剂提取法 ,提高了PCR扩增阳性率 ,对实际检案很有帮助 ;在PCR扩增前应常规进行DNA定量检验 ,否则对于重要检材应进行梯度扩增。     

国产圆珠笔油墨字迹书写时间的鉴别

对国产圆珠笔油墨字迹书写时间的鉴别进行了实验研究,达到了检测速度快,实用性强,费用低的效果.     

Comparison of ethyl glucuronide in hair with phosphatidylethanol in whole blood as post-mortem markers of alcohol abuse

Ethyl glucuronide (EtG) is a direct metabolite of ethanol and has been used as a marker of alcohol abuse in both urine and hair. This study investigated the value of EtG testing in post-mortem hair for diagnostic improvement of alcohol abuse in forensic medicine. Material from 70 consecutive medico-legal autopsies was collected in accordance with the recommendations on ethics by the Swedish National Board of Forensic Medicine. A method for determination of EtG in hair samples was developed using ultra performance liquid chromatography/electrospray tandem mass spectrometry (UPLC/ESI-MS/MS; LOQ, 2.5 pg/mg). The result of the EtG analysis was compared with the findings of phosphatidylethanol (PEth) in femoral whole blood, as measured by high performance liquid chromatography with an evaporative light-scattering detector (HPLC-ELSD; LOQ, 0.22 micromol/l). Evaluation of liver histology and anamnestic evidence of alcohol abuse of the deceased were taken in consideration for the interpretation. Measurable levels of EtG were present in 49 of the 70 autopsy cases whereas PEth was present in 36. Thirty-nine cases had EtG levels above the cutoff limit (> or = 30 pg/mg) compared with 29 for PEth (> or = 0.7 micromol/l). Fifteen cases had EtG as exclusive indicator for alcohol abuse compared with four cases for PEth. These findings suggest that measurements of EtG in hair may provide improved diagnostic information on alcohol abuse, due to a long retrospective time-window for detection and stability of EtG in hair in the decaying cadaver. However, an EtG level below the cutoff does not completely exclude previous alcohol abuse.     

利用压力循环仪提取骨骼DNA

目的探讨建立利用压力循环技术提取骨骼DNA的新方法。方法将11个不同部位骨骼样品分成3组,一组采用本实验室常规方法处理骨骼,一组采用压力循环仪处理骨骼,另外一组作为阴性对照,然后统一进行DNA的提取及定量。结果采用压力循环技术提取骨骼DNA时间比实验室常规方法缩短24小时以上,提取效率提高6%～49%。结论压力循环技术可以作为一种提取骨骼DNA提取的新方法之一。     

Evaluation of Commercial Kits for Dual Extraction of DNA and RNA from Human Body Fluids, ,

STR typing of DNA evidence can identify the donor with a high power of discrimination but cannot identify the tissue origin of a body‐fluid stain. Using RNA to attribute a crime scene stain to a particular tissue may aid in reconstruction efforts. With blood from 10 donors, four DNA and RNA coextraction kits were evaluated by measuring yields and STR and mRNA profiles. T tests indicated some significant differences in kit performance. The Zymo Research ZR‐Duet^? kit performed best based on average DNA (41.4 ng) and mRNA (4.07 ng) yields and was the only kit to provide complete DNA/RNA profiles for all samples. The consistency of this kit was challenged by data from additional blood and saliva donors. Further testing is advised before a superior kit is unequivocally chosen. Stand‐alone DNA or RNA purification generally offers higher yield, but coextraction may still allow successful STR profiling and tissue source identification.     

Advantage of ForensiX Swabs in Retrieving and Preserving Biological Fluids

This study compares two novel swabs (forensiX) with a standard cotton swab (EUROTUBE) for the collection of saliva stains on glass slide for STR analysis. ForensiX collection tubes are a standard cotton swab in an “active drying” tube, where swab sample is soon dried by its innovative tube surface of the wall. The other is forensiX Nylon Flocked Swab. The study is two phases: The first “phase” assesses swab types regarding to retrieve ability of saliva. The second “phase” compares the drying ability of each swab to assess how crime samples would fare when left in storage. The main result showed that “active drying” is effective to store swabbed sample. The forensiX swabs generally are effective for higher (twofold to fourfold) DNA yield compared to delta lab swab (around 750 pg and 250 pg from 0.5 μL of saliva), respectively. These findings demonstrate the importance of drying performance in the preservation of DNA and swab selection.     

Assessing the Utility of Soil DNA Extraction Kits for Increasing DNA Yields and Eliminating PCR Inhibitors from Buried Skeletal Remains

DNA identification of human remains is often necessary when decedents are skeletonized; however, poor DNA recovery and polymerase chain reaction (PCR) inhibition are frequently encountered, a situation exacerbated by burial. In this research, the utility of integrating soil DNA isolation kits into buried skeletal DNA analysis was evaluated and compared to a standard human DNA extraction kit and organic extraction. The soil kits successfully extracted skeletal DNA at quantities similar to standard methods, although the two kits tested, which differ mechanistically, were not equivalent. Further, the PCR inhibitors calcium and humic acid were effectively removed using the soil kits, whereas collagen was less so. Finally, concordant control region sequences were obtained from human skeletal remains using all four methods. Based on these comparisons, soil DNA isolation kits, which quickened the extraction process, proved to be a viable extraction technique for skeletal remains that resulted in positive identification of a decedent.     

A Concentrated Hydrochloric Acid-based Method for Complete Recovery of DNA from Bone

The successful extraction of DNA from historical or ancient animal bone is important for the analysis of discriminating genetic markers. Methods used currently rely on the digestion of bone with EDTA and proteinase K, followed by purification with phenol/chloroform and silica bed binding. We have developed a simple concentrated hydrochloric acid-based method that precludes the use of phenol/chloroform purification and can lead to a several-fold increase in DNA yield when compared to other commonly used methods. Concentrated hydrochloric acid was shown to dissolve most of the undigested bone and allowed the efficient recovery of DNA fragments <100 bases in length. This method should prove useful for the recovery of DNAs from highly degraded animal bone, such as that found in historical or ancient samples.