Long Allele Designations at D2S1338 and D19S433 Loci as Influenced by Various Multiplex STR Kits

European forensic laboratories are replacing the STR multiplex kits with the new generation 16/17 STR kits. This study examines the influence of the new generation kits and the new Applied Biosystems 3500xL Genetic Analyzer on the designation of long D2S1338 and D19S433 off‐ladder alleles. Different allele calls were obtained using the new NGM? (Applied Biosystems) and PowerPlex^® ESI? (Promega) kits compared with AmpF?STR^® SGM Plus? kit (Applied Biosystems). Sequence analysis was used to determine accurate allele designation. The new multiplex kits and the 3500xL Genetic Analyzer improved accuracy of long allele designations. DNA databases worldwide include countless profiles obtained by previous kits. Discrepancies between the new and former technologies may cause failure to detect hits. Discordance is expected due to primer sequence differences between various kits. An additional discordance, occurring in long alleles, independent of primer sequence is reported in this study.     

An Investigation of PCR Inhibition Using Plexor®‐Based Quantitative PCR and Short Tandem Repeat Amplification

A common problem in forensic DNA typing is PCR inhibition resulting in allele dropout and peak imbalance. In this paper, we have utilized the Plexor^® real‐time PCR quantification kit to evaluate PCR inhibition. This is performed by adding increasing concentrations of various inhibitors and evaluating changes in melt curves and PCR amplification efficiencies. Inhibitors examined included calcium, humic acid, collagen, phenol, tannic acid, hematin, melanin, urea, bile salts, EDTA, and guanidinium thiocyanate. Results were plotted and modeled using mathematical simulations. In general, we found that PCR inhibitors that bind DNA affect melt curves and C_T takeoff points while those that affect the Taq polymerase tend to affect the slope of the amplification curve. Mixed mode effects were also visible. Quantitative PCR results were then compared with subsequent STR amplification using the PowerPlex^® 16 HS System. The overall results demonstrate that real‐time PCR can be an effective method to evaluate PCR inhibition and predict its effects on subsequent STR amplifications.     

Atropine Eye Drops: An Unusual Homicidal Poisoning

In March 2009, the body of a 51‐year‐old man was found in the boot of his car. The body had been frozen before being dismembered at the abdomen. The autopsy failed to determine the cause of death. Systematic toxicological analyses of the victim's peripheral blood and urine showed the presence of atropine, a powerful anticholinergic. Atropine was therefore specifically detected and quantified throughout the victim's biologic samples by HPLC‐MS² in the biologic fluids and UHPLC‐MS² in the hair. The atropine concentrations were 887 ng/mL in the cardiac blood, 489 ng/mL in the peripheral blood, 6693 ng/mL in the gastric contents (1.1 μg), 6753 ng/mL in the urine, and 2290 pg/mg in the hair. The blood concentrations measured in the decedent were consistent with an overdose of atropine, which was determined as the cause of death. The manner of death was a homicide with criminal intent.     

广东壮族群体12个X-STR基因座的遗传多态性

目的 调查广东壮族群体DXS10103等12个 X-STR基因座的遗传多态性.方法 采用Investigator Argus X-12体系对200名广东壮族无关个体（男性100名,女性100名）进行12个X-STR的DNA分型.结果 该群体中12个X-STR基因座共检出143个等位基因,等位基因频率为0.0033～0.6433,等位基因分布均符合Hardy-Weinberg平衡.DXS10103与DXS10101基因座间存在连锁不平衡.各基因座的多态信息含量（PIC）为0.3944～0.9159,男性个体识别力（DPm）和女性个体识别力（DPf）分别为0.4815～0.9214和0.6441～0.9884,二联体和三联体的平均非父排除率分别为0.2625～0.8501（MECduo）和0.3944～0.9159（MECtrio）.累积男性个体识别力（CDPm）为0.999999998,累积女性个体识别力（CDPf）为0.999999999,累积二联体非父排除率（CMECduo）为0.999998271,累积三联体非父排除率（CMECtrio）为0.999999989.结论 Investigator Argus X-12系统在广东壮族群体中具有高度的多态性,本实验获得的群体数据可用于个体识别及亲缘关系鉴定案件的评估参考.     

浙江宣城地区汉族人群18个STR基因座遗传多态性

目的 调查浙江宣城地区汉族人群5000例无关个体18个STR基因座多态性分布.方法 应用AmpFlSTR Identifiler荧光标记复合扩增系统检测,统计计算群体遗传学参数.结果 18个STR基因座的基因型分布均符合Hardy-Weinberg平衡（P＞0.05）,共检出270个等位基因,频率在0.0001～0.5260之间,共有1289种基因型,在13个基因座上检出共44个微变异等位基因.18个基因座的杂合度观察值（Ho）在0.6238～0.9120之间,杂合度理论值（He）在0.6961～0.9601之间,多态信息含量（PIC）在0.5578～0.9126之间,累计个人识别率（TDP）为0.999 999 999 999 999 999 999 953,三联体累计非父排除概率（CPE）为0.999 999 993487 306,二联体累计非父排除率（CPE＊）为0.985819169.结论 本文调查结果与以往文献报道的不同地区民族的人群等位基因频率资料有一定程度的差异性.上述18个STR基因座适用于宣城地区汉族群体各类案件的法医学个体识别和亲权鉴定.     

24个基因座复合扩增系统的应用

目的建立24个基因座的复合扩增系统,并对其性能指标进行评价。方法选择24个基因座（包含D8S1179、D5S818、D2S1338、D18S51、D6S1043、D2S441、D3S1358、vWA、D19S433、D16S539、CSF1PO、Penta D、D22S1045、D13S317、D1S1656、D7S820、TPOX、Penta E、D10S1248、TH01、D12S391、D21S11、FGA等23个STR基因座及1个Amelogenin基因座）;合成引物,上游端标记荧光染料;收集DNA数据库建库血痕及口腔拭子样本及相关11种动物样本,采用本文方法进行复合扩增;并对方法的准确性、灵敏度、稳定性、种属特异性、检材适用性、混合样本的检验等系统性能指标进行验证。结果本文复合扩增系统对最长保存9年的各种血痕检材完整分型成功率为100%,且均衡性良好,无非特异性扩增,口腔拭子的成功率为97.8%,灵敏度达125pg,对含有抑制剂样本,在血红素浓度≤600μmol/L,腐殖酸浓度≤50ng/μL时检出效果稳定,种属特异性好。结论本文24个基因座复合扩增系统在DNA数据库建设中具有较好的应用价值。     

Genetic Polymorphism of Nine Non-CODIS STR Loci in Hu-nan Province-based Chinese Han Population

Objective To determine the allelic frequency distribution and genetic parameters of nine non-CODIS DNA index systems of the short tandem repeat （STR） loci （D2S1772, D6S1043, D7S3048, D8Sl132, DllS2368, D12S391, D13S325, D18S1364, and GATA198B05）. Methods A total of 353 blood samples were collected, extracted, amplified, and analyzed from unrelated healthy individuals of Han na- tionality in Hunan Province, China. Results One hundred and fourteen alleles were observed in the pop- ulation with corresponding allelic frequencies ranged from 0.001 0 to 0.323 0. For all the nine non-CODIS STR loci, the observed genotypic data showed no significant deviations from the Hardy-Weinberg equi- librium. The Ho, He, PIC, DP, and PE of the studied non-CODIS STR loci ranged from 0.108 0 to 0.1950, 0.805 0 to 0.8920, 0.7700 to 0.8600, 0.9250 to 0.9660 and 0.6070 to 0.7800, respectively. Conclusion Nine non-CODIS STR loci have high degrees of polymorphisms, which may be useful in in- dividual forensic identification and parentage testing in forensic practice.     

Quantification of psilocin in human whole blood using liquid chromatography–tandem mass spectrometry (LC–MS/MS)

There has been burgeoning interest in psilocybin-use for the treatment of various neurological and neurodegenerative diseases. Psilocybin is mistakenly perceived as the principal pharmacologically active compound due to its high concentrations found in magic mushrooms; however, it is the prodrug of psilocin. Despite the expanding body of clinical research seeking to understand the pharmacodynamic/pharmacokinetic properties of psilocin, and its role in inducing dramatic changes to cognitive function, there has not been a corresponding increase in the development of sensitive analytical methods that can quantify psilocin in different biological fluids. Existing analytical methods have been developed using plasma, serum, and urine as the matrix of choice, but with the unknown blood-to-plasma ratio of psilocin, any pharmacokinetic conclusions drawn solely on plasma data may be misleading. Thus, the main objective of this study is to develop the first analytical method that utilizes SPE and LC–MS/MS to quantify psilocin in human whole blood. The SPE procedure yielded a high recovery efficiency (≥89%) with minimal matrix effects. The method was validated according to ANSI/ASB 036 guidelines. Linearity was between 0.7–200 ng/mL and encompassed previously reported ranges found in plasma/serum. Bias, within- and between-run precision for all quality controls met ANSI/ASB 036 acceptability criteria. Endogenous/exogenous interferences and carryover were negligible. Psilocin stability was assessed at 4°C over 48 h and was considered stable. Although a proof-of-concept study will need to be performed to characterize the method, this analytical workflow was able to detect and quantify psilocin in human whole blood at low limits of quantification.     

福建汉族人群亲权鉴定中基因突变现象的观察分析

观察福建地区亲权鉴定中常用STR基因座突变现象,分析福建汉族人群遗传突变率和一些常用位点的突变情况。在3702例亲权关系鉴定的案例中,观察到79例发生基因突变,D8S1179、D21S11、D7S820等15个位点发生突变。     

A Comparison of DNA Extraction Using AutoMate Express™ and EZ1 Advanced XL from Liquid Blood,Bloodstains, and Semen Stains

In this study, DNA was extracted using an AutoMate Express? and an EZ1 Advanced XL from liquid blood, fresh and aged bloodstains, and fresh and aged semen stains. Extracted DNA was quantified by real‐time PCR using the D17Z1 locus. Short tandem repeat typing was performed using an AmpF?STR^® Identifiler kit. The yields of DNA obtained by the AutoMate Express? were higher from fresh bloodstains and fresh semen stains, almost the same from aged bloodstains and aged semen stains, but slightly lower from liquid blood compared with those obtained by the EZ1 Advanced XL. The addition of dithiothreitol or the use of PrepFiler? lysis buffer improved the EZ1 Advanced XL results from fresh bloodstains, but not for liquid blood and aged bloodstains. Our results demonstrated that the PrepFiler? lysis buffer is the main contributor to the higher DNA yields of the AutoM ate Express? for fresh bloodstains.