Developmental validation of the AmpFℓSTR® Identifiler® Plus PCR Amplification Kit: an established multiplex assay with improved performance

Abstract: Analysis of length polymorphism at short tandem repeat (STR) loci utilizing multiplex polymerase chain reaction (PCR) remains the primary method for genotyping forensic samples. The AmpF?STR^® Identifiler^® Plus PCR Amplification Kit is an improved version of the AmpF?STR^® Identifiler^® PCR Amplification Kit and amplifies the core CODIS loci: D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, TH01, TPOX, and vWA. Additional loci amplified in the multiplex reaction are the sex‐determinant, amelogenin, and two internationally accepted loci, D2S1338 and D19S433. While the primer sequences and dye configurations were unchanged, the AmpF?STR^® Identifiler^® Plus PCR Amplification Kit features an enhanced buffer formulation and an optimized PCR cycling protocol that increases sensitivity, provides better tolerance to PCR inhibitors, and improves performance on mixture samples. The AmpF?STR^® Identifiler^® Plus PCR Amplification Kit has been validated according to the FBI/National Standards and Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines. The validation results support the use of the AmpF?STR^® Identifiler^® Plus PCR Amplification Kit for human identity and parentage testing.     

Extended PCR conditions to reduce drop-out frequencies in low template STR typing including unequal mixtures

Forensic laboratories employ various approaches to obtain short tandem repeat (STR) profiles from minimal traces (<100 pg DNA input). Most approaches aim to sensitize DNA profiling by increasing the amplification level by a higher cycle number or enlarging the amount of PCR products analyzed during capillary electrophoresis. These methods have limitations when unequal mixtures are genotyped, since the major component will be over-amplified or over-loaded. This study explores an alternative strategy for improved detection of the minor components in low template (LT) DNA typing that may be better suited for the detection of the minor component in mixtures. The strategy increases the PCR amplification efficiency by extending the primer annealing time several folds. When the AmpF?STR^® Identifiler^® amplification parameters are changed to an annealing time of 20 min during all 28 cycles, the drop-out frequency is reduced for both pristine DNA and single or multiple donor mock case work samples. In addition, increased peak heights and slightly more drop-ins are observed while the heterozygous peak balance remains similar as with the conventional Identifiler protocol. By this extended protocol, full DNA profiles were obtained from only 12 sperm heads (which corresponds to 36 pg of DNA) that were collected by laser micro dissection. Notwithstanding the improved detection, allele drop-outs do persist, albeit in lower frequencies. Thus a LT interpretation strategy such as deducing consensus profiles from multiple independent amplifications is appropriate. The use of extended PCR conditions represents a general approach to improve detection of unequal mixtures as shown using four commercially available kits (AmpF?STR^® Identifiler, SEfiler Plus, NGM and Yfiler). The extended PCR protocol seems to amplify more of the molecules in LT samples during PCR, which results in a lower drop-out frequency.     

刃针短刺结合弥可保穴位注射治疗神经根型颈椎病80例

目的 观察刃针短刺结合弥可保穴位注射治疗神经根型颈椎病的疗效。方法 将156例神经根型颈椎病患者随机分为治疗组（80例）和对照组（76例）,治疗组采用刃针短刺结合弥可保穴位注射,对照组采用传统针刺法治疗,疗程15 d。观察两组治疗前后症状、体征积分,疼痛视觉模拟评分（visual analogue scale,VAS）分值,以及临床疗效。结果 治疗组治愈率及总有效率均显著高于对照组(P<0.05);与治疗前比较,两组治疗后症状、体征积分,疼痛VAS评分均显著减少(P<0.01);治疗后治疗组症状、体征积分及VAS评分显著低于对照组,治疗前后症状、体征积分差值及VAS评分差值显著高于对照组(P<0.01)。结论 刃针短刺结合弥可保穴位注射治疗神经根型颈椎病优于传统针刺法,临床值得推广应用。     

手机短信与网络诈骗犯罪

随着互联网技术的发展,手机消费将更多地与网络结合,手机短信的快捷、便利为人们生活带来方便的同时,也为犯罪分子所利用,出现了利用手机短信进行网络诈骗新型犯罪,通过对此类犯罪的特点、成因及预防几个方面阐述了自己的观点。     

AGCU免提取STR荧光检测试剂盒的验证

目的考察AGCU免提取STR荧光检测试剂盒．对保存在滤纸片或FTA卡上血液样本的直接扩增检测情况。方法使用人GCU免提取STR荧光检测试剂盒,对未经提取的滤纸片血液样本、FTA卡血液样本675份进行直接扩增和18个基因座的DNA分型,并对结果的可靠性进行研究。结果18个基因座检测结果与PP16和ID试剂盒分型结果一致,2000年数据库样本成功率92．3％,2001年数据库样本成功率92．6％,2004以后年数据样本及案件样本、亲子鉴定样本成功率在99％以上。结论AGCU试剂盒可以成功地对滤纸片、FTA卡样本的18个STR基因座进行直接扩增检测,检验结果稳定,分型准确。     

X—STR基因座的法医学应用研究进展

对X染色体的结构特征、遗传特征及其短串联重复序列（STR）基因座在法医学领域的研究历史、现状进行了综述。并分析了X染色体STR基因座在混合斑鉴定和复杂亲子关系鉴定中的应用,以及在法医学领域应用中应注意的问题．如单倍型和连锁不平衡现象等。     

Isolation and Individualization of Conceptus and Maternal Tissues from Abortions and Placentas for Parentage Testing in Cases of Rape and Abandoned Newborns*

Abstract: Abortion specimens are often submitted to forensic laboratories as the only piece of physical evidence in rape and incest cases. The recovery of conceptus tissues from this evidence permits the use of paternity testing to evaluate suspects. In cases of abandoned newborns, the recovery of maternal tissue from the placenta allows for the direct comparison of genetic profiles between the suspected mother and the biological mother. We report on the identification and isolation of conceptus tissues from embryonic‐ and fetal‐period abortions, and maternal tissues from delivered placentas, by gross and low‐magnification examination with manual dissection. Hundreds of single‐source samples have been successfully recovered by this method and short tandem repeat typed using standard forensic procedures. We additionally describe extraembryonic tissues that can be recovered and typed in the absence of the embryo proper. We conclude that an expertise and protocols can be developed by forensic laboratories for the routine analysis of this evidence.     

Full Sibling Identification by IBS Scoring Method and Establishment of the Query Table of Its Critical ValueCSCD

Objective: To establish a query table of IBS critical value and identification power for the detection systems with different numbers of STR loci under different false judgment standards. Methods: Samples of 267 pairs of full siblings and 360 pairs of unrelated individuals were collected and 19 autosomal STR loci were genotyped by Goldeneye™ 20A system. The full siblings were determined using IBS scoring method according to the 'Regulation for biological full sibling testing'. The critical values and identification power for the detection systems with different numbers of STR loci under different false judgment standards were calculated by theoretical methods. Results: According to the formal IBS scoring criteria, the identification power of full siblings and unrelated individuals was 0.764 0 and the rate of false judgment was 0. The results of theoretical calculation were consistent with that of sample observation. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci was successfully established. Conclusion: The IBS scoring method defined by the regulation has high detection efficiency and low false judgment rate, which provides a relatively conservative result. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci provides an important reference data for the result judgment of full sibling testing and owns a considerable practical value. © 2017 by the Editorial Department of Journal of Forensic Medicine.     

基于下一代测序的全解析度STR分型研究进展与展望

下一代测序技术具有高通量、高速度、集成化、低成本等显著优势,近年来已在科研和临床诊断领域得到广泛应用,在法医遗传学领域亦具有重要应用前景。当前主流的STR分型方法仅关注序列的长度多态性,然而由于核心重复结构存在差异或扩增区段内存在SNP,序列长度相等的等位基因可能是具有遗传稳定性的完全不同的等位基因,此类STR序列多态性是个体识别或亲缘关系分析的宝贵资源。基于下一代测序的STR分型在现有数据输出方式基础上,允许进一步关注STR的序列多态性,对STR基因座进行全解析度分型,显著提升STR基因座的个体识别能力。本文以法医STR遗传标记和下一代测序技术为关注焦点,系统综述基于下一代测序的全解析度STR分型领域国际最新研究进展,深入探讨该技术在法医DNA实验室的实际应用潜力和可能面临的挑战,希冀对相关研究和实践提供参考。     

Investigation of Different Ways in Which the CODIS 7.0 May be Used in Mass Disaster Identification

DNA analysis is a key method for the identification of human remains in mass disasters. Reference samples from relatives may be used to identify missing persons by kinship analysis. Different methods of applying the CODIS in disaster victim identification (DVI) were investigated. Two searches were evaluated: (i) relating family relatives to a pedigree tree (FPT) and (ii) relating unidentified human remains to a pedigree tree (UPT). A joint pedigree likelihood ratio (JPLR) and rank were calculated for each search. Both searches were similar in average JPLR and rank. In exceptional cases, namely the existence of a mutation different from the CODIS model, a nonbiological father, a mistake in STR, or incorrect profile association, the UPT search returned one true rank, whereas the FPT search returned no results. This paper suggests a novel strategy to overcome these limitations and increase efficiency in conducting identification of mass disaster victims.