共查询到18条相似文献,搜索用时 594 毫秒
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低拷贝模板STR分型及其存在的问题 总被引:20,自引:7,他引:13
微量、超微量生物学检材的STR分型常常是案件调查中进行DNA分析的难点。多年来 ,法医DNA分析工作者一直努力探索对微量DNA进行分析的方法。应用少于试剂盒规定的最小DNA模板量进行STR扩增检验 ,并对结果加以分析解释 ,被定义为低拷贝模板 (lowcopynumber ,LCN )STR分型[1、2 ] 。LCN STR分型不同于标准的STR分型 ,在实际应用中也存在许多问题需要引起注意[1~ 5] 。为了避免在LCN STR分型中出现误判 ,本文对如何正确地使用LCN STR分型技术加以介绍。1 LCN STR分型根据生产厂家的推荐 ,标准STR分型方法使用最低的模板… 相似文献
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目的研究PCR产物纯化对微量DNA的STR分型的影响。方法使用25pg/μL的9947标准基因组DNA为模板,标准程序扩增和STR分型检测。设立对照组A和实验组B、C、D。实验组分别使用分子筛(Qiagen DyeEX2.0spin kit)、超滤膜(Amicon Ultra-0.5,100KD)、亲和层析(Qiagen MinElute Column)3种DNA纯化方法,对照组不做任何处理。结果与对照组相比,3种方法均可显著提高STR分型强度(P峰高<0.001),平均峰高约为对照组的4倍,并且3种方法对提高STR分型强度无显著差异(P峰高=0.249)。结论 PCR产物纯化能显著提高微量DNA的STR分型强度,可用于骨骼、脱落细胞等微量DNA检材的检验。 相似文献
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目的 基于免疫磁珠法分离脱落上皮细胞中的白细胞,消除或减弱混合检材中血液来源STR分型对结果分析的干扰。方法 分别取两名不同个体的血液和口腔脱落上皮细胞,按不同比例制备成混合样本作为实验组,并同时制备细胞量相等的对照组。应用免疫磁珠法分离实验组样本中白细胞,并与对照组以相同条件进行DNA提取、扩增、分型,对比两组STR分型结果。结果 当血液量较少时,对照组为混合STR分型,经免疫磁珠法分离混合检材中白细胞后,实验组为单一来源STR分型;当血液量较多时,此时对照组为混合STR分型,但口腔脱落上皮细胞来源的STR分型谱带峰高较低甚至丢失,经免疫磁珠法后,实验组仍为STR混合分型,但口腔脱落上皮细胞来源的STR分型谱带成为主峰;当混合样本中口腔脱落上皮细胞微量,血液占比极大时,此时对照组为血液来源的单一STR分型结果,经免疫磁珠法后,实验组为STR混合分型,包含口腔脱落上皮细胞来源的所有等位基因分型。结论 该方法可用于分离脱落上皮细胞中血液成分,降低血液来源的DNA比例,能够改善此类混合检材中目的细胞的STR分型结果,为刑事案件中含有血迹浸染的混合生物检材的检验提供了一种新思路。 相似文献
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目的研究一次性使用牙刷上脱落细胞的DNA提取和STR分型。方法对一次性使用牙刷的采集方法、采集部位、DNA提取方法、存放时间对STR分型的影响进行比对研究。结果割取法可获得较高浓度的DNA,30例中检出9个以上基因座达27例,与擦拭法存在统计学差异(P〈0.05)。Chelex-100法、DNA IQTM法检出9个以上基因座分别为26例、24例,STR分型结果无统计学意义(P〉0.05)。提取牙刷的前、后部三束刷毛检出9个以上基因座分别达27例、28例,STR分型结果无统计学意义(P〉0.05);放置1天、1周、1个月、3个月、6个月的时间后检出9个以上基因座分别为28例、27例、22例、12例、7例。结论割取法提取一次性牙刷上的脱落细胞进行STR分型效果良好;放置时间越长的牙刷,检出率越低。 相似文献
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Forensic DNA analysis on microfluidic devices: a review 总被引:2,自引:0,他引:2
The advent of microfluidic technology for genetic analysis has begun to impact forensic science. Recent advances in microfluidic separation of short-tandem-repeat (STR) fragments has provided unprecedented potential for improving speed and efficiency of DNA typing. In addition, the analytical processes associated with sample preparation--which include cell sorting, DNA extraction, DNA quantitation, and DNA amplification--can all be integrated with the STR separation in a seamless manner. The current state of these microfluidic methods as well as their advantages and potential shortcomings are detailed. Recent advances in microfluidic device technology, as they pertain to forensic DNA typing, are discussed with a focus on the forensic community. 相似文献
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《Forensic Science International: Genetics Supplement Series》2013,4(1):e99-e100
This study performed the semen discrimination test, short tandem repeat (STR) typing, and Y-chromosome specific-STR (Y-STR) typing on five, 30–50-year-old semen stains. All samples reacted positively with the SM test reagent, and we observed sperm heads in all samples microscopically. The quantity of DNA extracted from the 43- and 50-year-old samples was much lower than from the other samples. STR typing of the 30-, 32-, 32-, 43-, and 50-year-old semen samples detected a maximum of 13, 15, 15, 11, and 6 of 15 loci, respectively, while Y-STR typing detected 16, 16, 16, 10, and 10 of 16 loci. These results suggest that the semen discrimination test and STR and Y-STR typing can detect extremely old semen stains and are useful for forensic practice. 相似文献
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《Forensic Science International: Genetics Supplement Series》2013,4(1):e133-e134
The NIST Standard Reference Material (SRM) 2391c: PCR-Based DNA Profiling Standard was designed for use in the standardization of forensic and paternity quality assurance procedures for fragment-based typing short tandem repeat (STR) alleles generated by the polymerase chain reaction (PCR). Certified genotypes of the 6 components A–F were assigned for 24 autosomal and 17 Y-STR markers plus Amelogenin using concordance testing between commercial kits. Selected Sanger sequencing characterization was performed for the alleles of 11 STR markers when only one PCR primer set was available for fragment-based typing. The goal is to characterize the remaining 30 STR loci in components A–C by Sanger sequencing methods for the STR repeat regions and adjacent flanking regions. Additional characterization of the SRM is intended to support the emerging interest in next-generation sequencing technologies for forensic typing applications. Sanger methods have detected underlying polymorphisms (sequence, insertion-deletion, variation in complex motifs) typically not detected by fragment-based typing. The sequenced regions include the commercial or known PCR binding sites commonly implemented in fragment-based typing. 相似文献
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The DNA purification step has been thought to be essential for typing of STR DNA. However, this process is time-consuming, and there is a risk of unexpected cross-contamination during purification. We report a new method for direct short tandem repeat (STR) amplification using a newly developed direct PCR buffer, AnyDirect, which can amplify STR loci from whole blood and blood- or saliva-spotted FTA cards without DNA purification. The autosomal and Y chromosomal STR loci were analyzed for whole blood and blood or saliva spots of random individuals, followed by comparison of the results with those of corresponding purified DNA. The results from whole blood and blood spots showed perfect concordance with those from purified DNA without allele or locus drop-out. However, in the case of saliva spots, no amplification or locus drop-out was observed in some of the samples, which offers a topic for further study. Additionally, some commercial hot-start DNA polymerases other than AmpliTaq Gold DNA polymerase were also found to be compatible with this buffer system. Therefore, this direct PCR buffer was demonstrated to be useful for fast forensic DNA analysis or criminal DNA databases for which there is no need to store DNA samples. 相似文献
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Peng Liu Stephanie H.I. Yeung Karin A. Crenshaw Cecelia A. Crouse James R. Scherer Richard A. Mathies 《Forensic Science International: Genetics Supplement Series》2008,2(4):301-309
An integrated lab-on-a-chip system has been developed and successfully utilized for real-time forensic short tandem repeat (STR) analysis. The microdevice comprises a 160-nL polymerase chain reaction reactor with an on-chip heater and a temperature sensor for thermal cycling, microvalves for fluidic manipulation, a co-injector for sizing standard injection, and a 7-cm-long separation channel for capillary electrophoretic analysis. A 9-plex autosomal STR typing system consisting of amelogenin and eight combined DNA index system (CODIS) core STR loci has been constructed and optimized for this real-time human identification study. Reproducible STR profiles of control DNA samples are obtained in 2 h and 30 min with ≤0.8 bp allele typing accuracy. The minimal amount of DNA required for a complete DNA profile is 100 copies. To critically evaluate the capabilities of our portable microsystem as well as its compatibility with crime scene investigation processes, real-time STR analyses were carried out at a mock crime scene prepared by the Palm Beach County Sheriff's Office (PBSO). Blood stain sample collection, DNA extraction, and STR analyses on the portable microsystem were conducted in the field, and a successful “mock” CODIS hit was generated on the suspect's sample within 6 h. This demonstration of on-site STR analysis establishes the feasibility of real-time DNA typing to identify the contributor of probative biological evidence at a crime scene and for real-time human identification. 相似文献
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目的建立荧光标记复合扩增检测4个STR基因座的方法,应用于法医学亲权鉴定与个人识别。方法用6-FAM标记D3S1754引物,HEX标记D4S2366和D12S375引物,TMR标记D1S549引物,PCR复合扩增,310基因分析仪电泳自动收集电泳结果数据,GeneScanAnalysisSoftware3.7NT计算扩增产物片段相对大小,Genotyper誖3.7NT软件进行样本基因型分型。将该方法应用于法医学亲权鉴定与个人识别。结果建立了荧光标记复合扩增检测4个STR基因座基因型的方法,具有良好的稳定性和较好的灵敏度,分型结果准确。结论研究建立的方法操作简便,分型结果稳定可靠,可用于遗传多态性研究和法医学亲权鉴定与个人识别。 相似文献
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Yeung SH Greenspoon SA McGuckian A Crouse CA Emrich CA Ban J Mathies RA 《Journal of forensic sciences》2006,51(4):740-747
A 96-channel microfabricated capillary array electrophoresis (muCAE) device was evaluated for forensic short tandem repeat (STR) typing using PowerPlex 16 and AmpFlSTR Profiler Plus multiplex PCR systems. The high-throughput muCAE system produced high-speed <30-min parallel sample separations with single-base resolution. Forty-eight previously analyzed single-source samples were accurately typed, as confirmed on an ABI Prism 310 and/or the Hitachi FMBIO II. Minor alleles in 3:1 mixture samples containing female and male DNA were reliably typed as well. The instrument produced full profiles from sample DNA down to 0.17 ng, a threshold similar to that found for the ABI 310. Seventeen nonprobative samples from various evidentiary biological stains were also correctly typed. The successful application of the muCAE device to actual forensic STR typing samples is a significant step toward the development of a completely integrated STR analysis microdevice. 相似文献