Mucosal Cell Isolation and Analysis from Cellular Mixtures of Three Contributors

In forensic genetic analyses, mixtures of various biological materials are common samples. Micromanipulation, which is performed based on differences in cellular morphology, is an effective method for the isolation of cells from mixtures. In this study, mucosal cell was isolated from somatic cellular mixtures (blood and saliva) based on micromanipulation and a low volume‐PCR (LV‐PCR) platform. One hundred and twenty‐six parallel LV‐PCR processes were performed using an Identifiler^® kit, with 107 reactions yielding single‐source DNA profiles. Among them, 54 full profiles (50%) and 37 partial profiles (13–15 loci) were obtained. Based on the above method, we obtained a single‐source DNA profile from a cigarette butt contaminated by two victims’ blood in a murder case. The generated genotype was used to query a DNA database, and a perfect match was found.     

Recovery of DNA from Latent Fingerprint Tape Lifts Archived Against Matte Acetate

This study was driven by court order to examine methods to remove, extract, and STR‐type potential DNA entrapped between latent fingerprint lifting tape and matte acetate that was collected from a 1977 crime scene. Results indicate that recovery of appreciable quantities of DNA is more challenging once adhesive is attached to matte acetate cards and even more difficult when fixed following black powder enhancement. STR amplification of extracts from entrapped fingermarks collected following the dusting/lifting procedure did not produce robust profiles, and extraneous peaks not expressed by print donors were detected for some samples. A hearing was set to argue whether there was DNA remaining to be tested, and if so, whether that DNA could be exculpatory in this postconviction matter. The studies herein provided the basis for the court's decision to not require the testing.     

PE‐Swab Direct STR Amplification of Forensic Touch DNA Samples

The PE‐Swab direct STR amplification workflow was developed to process low‐level “touch DNA” samples. In this workflow, a forensic sample is first collected on a 4‐mm PE‐Swab (a novel sample collection device); two 2‐mm punches containing collected samples are then generated from the PE‐Swab and directly amplified for STR typing. Compared to the conventional STR workflow, which involves DNA extraction, purification, and elution volume reduction, the PE‐Swab direct STR amplification workflow does not require sample preparation and takes <60 sec before a touch sample is ready for STR amplification. Because there is no DNA loss due to sample preparation, the PE‐Swab workflow is more sensitive than the conventional STR workflow. The average peak height per sample obtained by the PE‐swab workflow is 3 times higher than that from the conventional workflow with both low‐level single source and two‐contributor mixture samples tested in this study.     

Reduction of Powerplex® Y23 Reaction Volume for Genotyping Buccal Cell Samples on FTATM Cards

PowerPlex^® Y23 is a novel kit for Y‐STR typing that includes new highly discriminating loci. The Israel DNA Database laboratory has recently adopted it for routine Y‐STR analysis. This study examined PCR amplification from 1.2‐mm FTA punch in reduced volumes of 5 and 10 μL. Direct amplification and washing of the FTA punches were examined in different PCR cycle numbers. One short robotically performed wash was found to improve the quality and the percent of profiles obtained. The optimal PCR cycle number was determined for 5 and 10 μL reaction volumes. The percent of obtained profiles, color balance, and reproducibility were examined. High‐quality profiles were achieved in 90% and 88% of the samples amplified in 5 and 10 μL, respectively, in the first attempt. Volume reduction to 5 μL has a vast economic impact especially for DNA database laboratories.     

Polymorphism of four X-chromosomal STR loci in Belarusians and Slovaks

We have investigated four X-chromosomal STR loci (a tetranucleotide repeat marker HPRTB, DXS7423 and trinucleotide repeat systems DXS101, DXS8377) in population samples of unrelated Belarusian and Slovak males (N = 180 and 116, respectively).Markers were amplified in a multiplex PCR reaction with primers labeled with fluorescent dyes 5-FAM and 5-JOE (dye set F). The separation and detection of PCR products were performed by capillary electrophoresis on a 3130 Genetic Analyzer (Applied Biosystems), using positive controls (K562 and NA9947A) and the GeneScan-500 ROX internal lane standard. Allele designation was based on comparison with the constructed allelic ladder. We performed statistical analysis estimating power of discrimination for males (PD_male). Our data was compared with European populations from Poland and Germany. The obtained data are useful in forensic practice and they contribute to creation of national X-STR databases in Belarus and Slovakia.     

印记基因KCNQ1的遗传多态性及在亲权鉴定中的应用

目的为了调查印记基因KCNQ1的STR位点在中国汉族人群中的遗传多态性，利用亲源印记等位基因（parentally imprinting allele，PIA）分型法确定孩子的等位基因亲代来源，为亲权鉴定提供新的侯选STR位点。方法应用Chelex法提取153例佳木斯地区汉族健康无血缘关系个体DNA，用QIAamp Blood Kit（Qiagen）法提取3个家庭10个个体DNA，PCR扩增，凝胶电泳分型，ABIPRISM^TM 3730XL DNA测序仪测序；甲基化敏感性限制性内切酶消化孩子基因组DNA，PCR扩增，确定孩子等位基因的亲代来源。结果发现在中国佳木斯地区汉族人群中KCNQ1基因的STR有7个等位基因，多态信息含量为0．662，且KCNQ1基因的STR位点呈父源印记。结论印记基因KCNQ1的STR位点有很好的多态性，可为亲权鉴定提供新的侯选遗传标记，其亲源特异性甲基化标记有望应用于单亲鉴定中。     

Analysis of 8 STR of the X-chromosome in two Italian regions (Umbria and Sardinia)

Eight X-chromosome STR were investigated in two groups of individuals from two Italian regions, Umbria and Sardinia. These two regions have a very different history. Umbria, situated in the centre of Italy and without defensive natural barriers, in the course of the centuries has been object of many invasions and appropriations by foreign people. On the contrary, Sardinia, an island in the centre of the Mediterranean sea, has endured a minor number of foreign invasions. The ChrX markers were amplified in a pentaplex (DXS6789, DXS7423, DXS6807, DXS101, DXS8377) and a triplex (DXS10074, DXS10075, DXS10079) that represents a haplotype. The DNA was extracted from 200 blood samples using the QIAmp DNA Minikit (Qiagen™). Amplification products were detected on an ABI PRISM 310 Genetic Analyzer (Applied Biosystems), using the same dye labels, run conditions, standard (GeneScan 500 Liz) and matrix file of AmpFlSTRIdentifiler. Statistical analyses for all the loci and intergroup comparisons between the two regional groups of individuals were performed.     

原发性高血压早期肾损害中医证型与血、尿β2-MG及尿ALB、IgG的关系

目的: 探讨原发性高血压(EH)早期亚临床肾损害与中医证型的关系.方法:参照国家卫生部<新药(中药)治疗高血压病临床研究指导原则>的中医辨证分型标准,对127例EH患者进行了中医辨证分型,采用放射免疫分析法(RIA)进行肾功能联检(血、尿β2-MG,尿ALB和IgG),并以健康人50例作对照.结果: ①轻、中及重度高血压患者的早期肾功能指标和正常人比较,差异有显著性(P<0.05),高血压病程<5年的早期肾功能指标与>5年者比较,差异有显著性(P<0.05或P<0.01);②中医辨证分型以阴虚阳亢证最多,其中肝火亢盛证肾损害较轻,阴虚阳亢证肾损害有加重趋势,但两者比较无显著性差异(P>0.05),痰湿壅盛证和阴阳两虚证肾损害进一步加重.结论:中医证候和EH早期肾损害程度有一定的关系,中医不同证型之间存在着客观化指标的区别,肾功能联检对高血压并发早期肾损害有重要意义.     

Validation of SRY Marker for Forensic Casework Analysis

Abstract:  Determining the gender of the source of forensic DNA evidence is based on the amelogenin test. However, at times the assay may not be indicative of gender assignment, because of deletions at the amelogenin site. Previously, we described successful coamplification of a marker residing within the SRY gene with the short tandem repeat markers from two commercially available human identification kits. The study herein addresses the validation of primers for the target SRY gene regarding specificity, sensitivity, and robustness. Among 115 unrelated male Slovenians no null allele was observed. Repeatable and reliable results were obtained from as little as 25 pg of template DNA, indicating a high sensitivity of detection for the assay. No polymerase chain reaction product was observed even at a concentration of 10 ng/μL of template female DNA. Additionally, the male specific marker could be detected in mixed male and female samples down to a ratio of 1:16.     

New optimized DNA extraction protocol for fingerprints deposited on a special self-adhesive security seal and other latent samples used for human identification

Abstract: Obtaining complete short tandem repeat (STR) profiles from fingerprints containing minimal amounts of DNA, using standard extraction techniques, can be difficult. The aim of this study was to evaluate a new kit, Fingerprint DNA Finder (FDF Kit), recently launched for the extraction of DNA and STR profiling from fingerprints placed on a special device known as Self‐Adhesive Security Seal Sticker^® and other latent fingerprints on forensic evidentiary material like metallic guns. The DNA extraction system is based on a reversal of the silica principle, and all the potential inhibiting substances are retained on the surface of a special adsorbent, while nucleic acids are not bound and remain in solution dramatically improving DNA recovery. DNA yield was quite variable among the samples tested, rendering in most of the cases (>90%) complete STR profiles, free of PCR inhibitors, and devoid of artifacts. Even samples with DNA amount below 100 pg could be successfully analyzed.