激光显微捕获技术用于尿液脱落细胞DNA检测

目的采用激光显微捕获技术（LCM）捕获尿液脱落细胞,并进行STR分型。方法收集10份健康成人尿液样本,根据储存时间分组,其中新鲜尿液组（≤24h）分别采用Chelex-100及LCM联合DNA IQTM提取法提取DNA,储存尿液组（〉24h）再分为4℃组和室温组,分别在4～30d内不同时间点采用LCM联合DNA IQTM提取法提取DNA;各组提取的模板DNA进行扩增及SRT分型检验。结果新鲜尿液组采用LCM联合DNA IQTM提取法提取DNA,所有样本均可检出全部基因座（16个）,采用Chelex-100法则在部分基因座上出现等位基因丢失、非特异性扩增、峰值低等现象;4℃储存10d和室温储存4d以内的尿液经检验可明确判读12个以上基因座,4℃20～30d及室温7d,可检出7个以上基因座。结论 LCM技术可用于尿液检材的DNA分型检验,且检材应尽可能4℃保存并尽快检验。     

烟蒂DNA分型的研究

目的 研究烟蒂中DNA提取及其检验。方法 用Chelex-100法提取170枚烟蒂样本的DNA,进行PCR扩增及STR检验。结果 除1名志愿者提供的21枚烟蒂外层纸未能检出STR基因分型外,其余烟蒂外层纸均得到分型结果。加入少许烟丝的样本未能检出STR分型,与口唇接触的海绵有时可检出基因型,6个月内的烟蒂可检出小片段基因座。结论 烟蒂能进行DNA分型,在法医检案中具有应用价值。     

尿液中DNA的提取与检验

尿液中DNA的STR分型检验有一定的应用价值:国外文献报道过应用于运动员兴奋剂控制^[1]中可疑尿检样品的个体识别,国内则偶有案发现场提取到尿液、尿冰、尿斑并成功进行个体识别的案例报道。与血液、精斑、唾液等检材相比,尿液STR分型的检出率较低,主要是与尿液中的成份有关。本文重点分析人类尿液成分,分类总结目前可用于提取尿液中DNA的多种方法,分析可能影响尿液STR分型检验结果的因素。     

存放5d尿液检验DNA成功1例

尿液中的尿素、尿酸等对细胞中的DNA有破坏降解作用,因此样本存放时间是影响尿液DNA检验成功率的主要因素之一。本例对室温放置5d的尿液进行成功检测,现报道如下。1案情2007年5月,曲靖市某企业一办公室被盗,在现场垃圾桶塑料袋内发现有浓烈尿臊味淡黄色液体。据调查,垃圾桶中塑料袋为新换干净塑料袋,分析其内     

车辆上脱落细胞STR检验

目的对汽车方向盘及变速杆把手上的皮肤脱落细胞进行STR检验研究。方法用EZ-tape采集车辆方向盘及变速杆上的脱落细胞,Chelex-100法与磁珠法结合提取DNA,延长保温时间。定量后调整PCR反应体系,适当增加PCR循环数,增加PCR产物量及延长进样时间进行电泳检测,使用GeneMapperIDV3.2软件进行STR分型。同时,对比使用多重置换扩增技术对提取的DNA进行全基因组扩增。结果对33份车辆方向盘和变速杆上脱落细胞的检测,其中19份检出全部基因座的基因分型结果,9份检出部分基因型,5份未检出DNA分型结果。而利用多重置换扩增技术未获得满意图谱。结论本研究建立的脱落细胞收集、DNA提取、PCR扩增及检测方法适合于车辆上脱落细胞的检验,其结果优于使用多重置换扩增技术获得的分型。     

车辆上脱落细胞STR检验

目的对汽车方向盘及变速杆把手上的皮肤脱落细胞进行STR检验研究。方法用EZ-tape采集车辆方向盘及变速杆上的脱落细胞,Chelex-100法与磁珠法结合提取DNA,延长保温时间。定量后调整PCR反应体系,适当增加PCR循环数,增加PCR产物量及延长进样时间进行电泳检测,使用GeneMapperIDV3.2软件进行STR分型。同时,对比使用多重置换扩增技术对提取的DNA进行全基因组扩增。结果对33份车辆方向盘和变速杆上脱落细胞的检测,其中19份检出全部基因座的基因分型结果,9份检出部分基因型,5份未检出DNA分型结果。而利用多重置换扩增技术未获得满意图谱。结论本研究建立的脱落细胞收集、DNA提取、PCR扩增及检测方法适合于车辆上脱落细胞的检验,其结果优于使用多重置换扩增技术获得的分型。     

双差异分离法对混合斑快速检验的初探

目的建立强奸案中混合斑的分离检验新方法,并评估其应用价值。方法采用双差异分离法对人工制备的3个不同浓度的模拟混合斑样本及相应滤膜进行分离提取,对所得DNA进行定量分析和STR分型检验。结果不同浓度的3个样本经孔径为10μm尼龙网格膜两次离心过膜后精子细胞损耗率均小于3%,同时3个样本沉淀均检出完整单一的男性STR分型。结论该双差异分离法所用滤膜对精子细胞DNA的损耗极少并且具有稳定性;该方法用于精阴混合斑的分离检验,具有高分离效率,装置简单,操作便捷,成本低廉等优势,为性侵案中混合斑的分离检验提供了一种新思路。     

应用SNaPshot技术检测精液特异性cSNP遗传标记

目的 探讨基于SNaPshot技术的精液特异性编码区单核苷酸多态性（codingregionsinglenucleotidepolymorphism,cSNP）遗传标记检测在精液（斑）溯源及混合体液（斑）鉴定中的可行性。方法 制备16例精液斑和11例精液-静脉血混合斑样本,提取其基因组DNA(genomicDNA,gDNA)和总RNA,并将总RNA逆转录为互补DNA(complementaryDNA,cDNA)。在已验证的精液特异性mRNA编码基因上筛选cSNP遗传标记。基于SNaPshot技术构建cSNP复合检测体系并通过CE对样本进行基因分型。结果 成功构建了包含5个精液特异性cSNP的复合检测体系。在16例精液样本中,除了位于TGM4基因上的cSNP在cDNA的检测结果中出现等位基因丢失外,其余cSNP的gDNA和cDNA分型结果高度一致。检测精液-静脉血混合斑时,检出的cSNP分型结果均与精液提供者的基因型一致,未受到静脉血提供者基因型的干扰。结论应用SNaPshot技术检测精液特异性cSNP的方法可以应用于法医学精液（斑）的基因分型,并为混合体液（斑）中精液来源个体的判定提供...     

限制性组合分析法推定男女混合斑中个体分型初探

正混合斑是指包含两名或两名以上个体的混合生物检材,在多数情况下,此类检材的DNA分型往往表现为两人或多人的混合分型,使结果分析较为复杂[1]。本文尝试采用2005年国际法医遗传学会(ISFG)推荐的关于混合斑结果分析中的计算方法对混合斑案件中单一个体DNA分型结果进行分析。1材料与方法1.1样本及检验样本由公安部物证鉴定中心提供强奸案件中床单上混合斑检材1份,为日常检案积累,根据案情调查证实该检材系混合斑。DNA检验采用Chelex法提取上述检材DNA,经DNATyperTM15 plus试剂盒扩增后在ABI 3130遗     

改良差异裂解法结合硅珠法提取混合斑精子DNA

目的采用改良差异裂解法结合硅珠法提取混合斑中精子DNA,并评价其应用价值。方法收集52例经常规差异裂解法检验含有女性分型的混合斑检材,采用改良差异裂解法结合硅珠法提取精子细胞DNA,IdentifilerTM试剂盒进行PCR扩增检验。并将常规差异裂解法结果作为对照。结果52例混合斑检材中,采用改良差异裂解法结合硅珠法检出单一男性精子成分有38例,男性分型检出率达到98．08％。结论改良差异裂解法结合硅珠法适合提取混合斑中精子DNA。     

Usefulness of dura mater in providing DNA samples for identifying cadavers

We examined the usefulness of the dura mater in identifying human remains. Dura mater was collected from 50 cadavers, including drowned, charred, and mummified remains. The STR genotype using the AmpFlSTR Identifiler Kit could be typed at 15 STR and amelogenin loci in 30 samples of 33 cases. Furthermore, the ABO genotype and amelogenin using gel-based methods could be typed in 44 samples of 50 cases. In cases with successful typing of STR, ABO-DNA, and amelogenin, the longest time after death was from 12 to 26 days in a drowned body. The minimum quantity of dura mater required for DNA extraction was about 2.5 mg, dried and fixed by ethanol, in a cadaver 15 h after death. The state of the DNA from the dura mater from the calvaria may be better than that from the basis cranii interna. We found that DNA from dura mater is one of the most useful samples for forensic identification.     

A simple method of DNA extraction and STR typing from urine samples using a commercially available DNA/RNA extraction kit

We devised a simple DNA extraction procedure suitable for STR typing of urine sample. Use of a commercially available DNA/RNA extraction kit equipped with a silica-gel-based membrane made it possible to omit the recovery of urinary nucleated cells by sedimentation before the extraction. Successful genotyping of the TH01, HumTPO and multiplex STRs was achieved using aliquots of urine as small as 100 microL. Furthermore, application of this DNA extraction procedure to frozen urine samples provided STR allele results comparable to results obtained from fresh samples. Therefore, this extraction procedure is considered to be effective for STR typing of urine samples in both the frozen and aqueous state. Furthermore, addition of sodium azide to fresh urine samples prolonged their storage duration even at room temperature.     

DNA IQ磁珠法结合Maxwell~（TM） 16自动仪提取接触DNA

目的研究DNA IQ磁珠法结合MaxwellTM 16自动仪对接触DNA提取的应用价值。方法 151份案件接触DNA检材95℃裂解后,采用DNA IQ磁珠法结合MaxwellTM 16自动仪提取DNA,然后进行DNA定量和STR分型检测,统计各种类型的接触DNA含量I、PC CT值和STR分型成功率。结果 151份案件接触DNA检材中,除果核平均DNA获得量为9.51ng以外,其它接触检材的平均DNA获得量均大于10ng,烟蒂检验成功率最高为93%,果核检验成功率较低,为60%。所有DNA样品的IPC CT值均在27左右,纯度高。结论大部分接触DNA检材采用DNA IQ磁珠法结合MaxwellTM 16自动仪可提取到足以进行STR分型的DNA。     

吸附性载体上微量血痕的DNA分型

目的研究吸附性载体上微量血痕的DNA提取及其检验。方法用Chelex-100法、QIAamp MiniKit、及QIAamp Mini Kit改良法提取吸附性载体上微量血痕中的DNA,进行PCR扩增及STR检验。结果采用Chelex-100法及QIAamp Mini Kit的分型成功率很低;采用QIAamp Mini Kit的改良法能较好的得到分型图谱。结论采用QIAamp Mini Kit的改良法能较好的提取吸附性载体上微量血痕的模板DNA。     

Comparisons of protocols for enhanced DNA profile quality from FTA®-deposited urine samples

Disputes over the identity of a urine sample donor have been reported, and urine authentication by genetic profiling has helped resolved the cases. However, since genotyping of urine is not always required, many drug-testing laboratories may face sample storage issues. Several studies have investigated the use of FTA® cards as a convenient tool for keeping specimen at room temperature for extended periods of time. However, generating complete STR profile from some FTA®-deposited urine samples remains challenging due to low levels of genetic material content, necessitating amendments to the laboratory’s standard protocols. This work therefore aims to evaluate the effects of two DNA template preparation methods, both employing FTA® cards as the storage medium, on the success rates of STR profiling from urine. Specimen from a female volunteer, representing a particularly low-yield sample, was employed. Aliquots of 1 and 2 mL were used as the starting material to evaluate DNA template preparation using the FTA® manufacturer’s protocol for disc purification against elution of DNA from the FTA® using Prepfiler™ Forensic DNA Extraction Kit. AmpFℓSTR™ Identifiler™ Plus PCR Amplification Kit was used to amplify the STR markers, and the PCR products were analysed using Applied Biosystems™ 3500xL Genetic Analyzer. The DNA profile qualities were examined in terms of number of loci detected and peak height balance. Comparisons with the profiles obtained from DNA isolated using QIAamp® DNA Micro Kit from 1 and 2 mL of the same batch of urine were also made. The optimised protocol was then tested on urine samples from three male volunteers. The results showed that the purification of FTA® punches according to the manufacturer’s protocol enabled full DNA profiles to be obtained from both 1 and 2 mL of urine from all samples tested, including male samples. In contrast, no DNA profile could be generated from the DNA eluted with the Prepfiler™ kit. When compared with the more conventional solid-phase DNA extraction method, the profiles generated from the FTA® punches exhibited similar reproducibility and quality to those from the template isolated by the QIAamp® Kit. This work further demonstrated the feasibility of FTA® cards as a tool for specimen storage and DNA template preparation from small volumes of urine for authentication by STR profiling. Full STR profiles could be generated from sample from both sexes without modification of the PCR conditions or injection time.     

Successful DNA typing of urine stains using a DNA purification kit following dialfiltration

To evaluate the utility of DNA polymorphism typing of urine stains in forensic investigations, the amplifiable amount of DNA was estimated in 20 urine specimens obtained from 10 male and 10 female volunteers using a DNA purification kit following dialfiltration. DNA obtained from both urine and urine stains was amplified with the AmpflSTR Profiler PCR Amplification Kit, and was analyzed by capillary electrophoresis using the Genetic Analyzer. The amount of male and female urine necessary for obtaining a complete DNA profile was 0.2 mL and 0.08 mL, respectively. When 0.2 mL of male urine were used to create urine stains, complete DNA profiles could be obtained from just some of the stains. However, when only 0.1 mL of female urine was used, complete profiles could be successfully obtained from all of the stains. DNA on bleached cotton remained amplifiable for 3-6 weeks. This method using a DNA purification kit following dialfiltration can be recommended for the genotyping of urine stains.     

氨基比林血痕预试验处理血痕后样本的DNA定量

目的：探讨氨基比林血痕预试验处理血痕后样本DNA含量的变化及对STR分型检测的影响。方法10名健康无关个体EDTA抗凝血液制成滤纸血痕,氨基比林血痕预试验检测,按试验后血样干燥保存时间分30 min、1 h、3 h、6 h、12 h、24 h共6个实验组,并采用磁珠法、QIAcube DNA纯化法、Chelex-100法三种方法提取样本DNA,应用荧光定量PCR检测样本DNA含量,PCR-STR荧光技术进行STR分型。结果提取方法相同时,氨基比林血痕预试验后血样随干燥保存时间的延长,样本DNA含量呈逐渐降低的趋势。保存时间相同时,不同DNA提取方法间,样本DNA含量差异也有统计学意义。90.56%样本均可获得16个STR基因座明确分型。结论氨基比林血痕预试验对血痕样本DNA有损伤,24 h内多可获有效STR分型。磁珠法提取样本DNA进行STR分型,效果最好。     

A Simple and Efficient Method of Extracting DNA from Aged Bones and Teeth

DNA is often difficult to extract from old bones and teeth due to low levels of DNA and high levels of degradation. This study established a simple yet efficient method for extracting DNA from 20 aged bones and teeth (approximately 60 years old). Based on the concentration and STR typing results, the new method of DNA extraction (OM) developed in this study was compared with the PrepFiler? BTA Forensic DNA Extraction Kit (BM). The total amount of DNA extracted using the OM method was not significantly different from that extracted using the commercial kit (p > 0.05). However, the number of STR loci detected was significantly higher in the samples processed using the OM method than using the BM method (p < 0.05). This study aimed to establish a DNA extraction method for aged bones and teeth to improve the detection rate of STR typing and reduce costs compared to the BM technique.