TWGDAM validation of a nine-locus and a four-locus fluorescent STR multiplex system

The Gene Print PowerPlex 1.1/Amelogenin and FFFL Fluorescent STR Systems have been validated following the recommendations presented by the Technical Working Group on DNA Analysis Methods (TWGDAM). The PowerPlex 1.1/Amelogenin System supports simultaneous amplification of eight short tandem repeat loci and the Amelogenin gender identification marker. The loci D16S539, D7S820, D13S317, and D5S818 are labeled with fluorescein (FL) while the loci CSF1PO, TP0X, TH01, vWA and Amelogenin are labeled with carboxy-tetramethylrhodamine (TMR). The FFFL Multiplex System is composed of the loci F13A01, FESFPS, F13B, and LPL, each labeled with fluorescein. We have observed no overlap of alleles across loci labeled with an individual fluorescent dye. Samples of each system were amplified and labeled in a single reaction, separated by electrophoresis through a denaturing polyacrylamide gel, and amplified alleles detected using a Hitachi FMBIO Fluorescent Scanner. Alterations from the standard amplification protocols in cycle number and annealing temperature generally produced excellent results. In experiments testing sensitivity as little as 0.2 ng of DNA template could be detected. As expected, different body fluids from the same individuals generated identical DNA profile results. Template DNA derived from blood-strains deposited on a variety of matrix supports displayed robust amplification except for material derived from deposits on wood and Japanese orchid leaves. Mixtures of DNA templates could be interpreted with the minor component present in as little as ten percent of the total sample. Monoplex and multiplex amplifications produced identical amplified allele patterns, indicating that STR multiplex systems save template and increase efficiency in the amplification procedure without loss of quality. Analyses of genotype frequencies in African-American, Caucasian-American and Hispanic-American populations using all twelve loci were used to determine matching probabilities smaller than 1 in 1.14 x 10(8) and 1 in 2658 for the PowerPlex 1.1 and the FFFL Multiplex Systems, respectively. The matching probability achieved with the two systems combined is smaller than 1 in 3.03 x 10(11). The independence of alleles within loci was generally demonstrated by applying the exact test to demonstrate Hardy-Weinberg Equilibrium. All of the studies performed indicate that the PowerPlex 1.1/Amelogenin and FFFL Multiplex Systems are powerful, robust, and reliable investigative tools that can be used in the analysis of forensic samples.     

Validation of a 16-locus fluorescent multiplex system

STR multiplexes have been indispensable for the efficient genotyping of forensic samples. The PowerPlex 16 System contains the coreCODIS loci, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, THOI, TPOX, vWA, the sex determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. This multiplex satisfies the locus requirements for most national databases and is the most efficient currently available system due to its single PCR amplification. To provide the groundwork for judicial acceptance, including the publication of primer sequences, and to evaluate laboratory-to-laboratory variation, a developmental validation for casework on this commercially available system was performed in 24 laboratories and produced the following conclusions. Amplification was reliable on a variety of thermal cyclers and product could be analyzed on either an ABI PRISM 310 Genetic Analyzer or an ABI PRISM 377 DNA Sequencer. Genotyping using single source samples was consistent between 0.25 and 2 ng of input DNA template with a few laboratories obtaining complete genotypes at 0.0625 ng. However, heterozygote allele imbalance (<60% peak height balance) caused by stochastic effects was observed at a rate of 13% with 0.125 ng DNA and 22% at 0.0625 ng DNA. Mixture analyses were done using a total of 1 ng of DNA template. Most alleles were detected in mixtures of 4 to 1 and some minor alleles were detected in mixtures of 19 to 1. Optimum amplification cycle number was dependent on the sensitivity of the detection instrument used and could also be adjusted to accommodate larger amounts of DNA on solid supports such as FTA paper. Reaction conditions including volume, annealing temperature, and concentrations of primer, AmpliTaq Gold, and magnesium were shown to be optimal yet robust enough to withstand moderate variations without affecting genotype analysis. Environmental, matrix and standard source analyses revealed an ability to obtain complete genotypes in all sample types except those exposed to 80 degrees C for 12-48 days. Finally, comparison of genotype results from the PowerPlex 16 System with other commercially available systems on non-probative reference and forensic samples showed consistent results.     

Validation and implementation of the PowerPlex 16 BIO System STR multiplex for forensic casework

The PowerPlex 16 BIO multiplex short tandem repeat (STR) system contains the 13 CODIS loci (FGA, TPOX, D8S1179, vWA, D18S51, D21S11, TH01, D3S1358, CSF1PO, D16S539, D7S820, D13S317, and DS5S818), plus two pentanucleotide repeat loci (Penta D and Penta E) and the sex-identifying locus. Amelogenin. The PowerPlex 16 BIO System is optimized for use with the Hitachi FMBIO gel imaging systems. A consortium of seven independent laboratories collaborated to perform the studies defined by the FBI standards for performing a developmental validation, including the evaluation of sample concordance, percent stutter determination, nonprobative casework, precision, sensitivity, mixture determination, effect of substrates, the impact of environmental insults, and species specificity. All samples tested for concordance were consistent except for one sample from the Virginia Division of Forensic Science database that displayed discordance at D13S317, a locus whose primer sequence was altered. Stutter values were comparable to those of other STR multiplex systems, the precision was comparable to other multiplexes analyzed by gel electrophoresis, the DNA profiles were unchanged by the substrate upon which the blood samples were placed, and the nonprobative casework samples re-typed for the PowerPlex 16 BIO System were consistent with previous typing results. When greater than 0.125 ng of DNA was placed into the PowerPlex 16 BIO System amplification reaction, a full profile was generated by all laboratories. The mixture study results were comparable to those reported for other multiplex systems, the environmental study demonstrated a loss of larger molecular weight loci when samples were incubated at elevated temperatures for a prolonged period of time, and the only notable cross species hybridization was observed with primate DNA samples. This extensive validation work performed demonstrates that the PowerPlex 16 BIO System provides STR data of a quality comparable with other PowerPlex STR multiplex kits as well as other widely used STR multiplexes and is thus suitable for evidentiary casework analysis as well as database sample profiling.     

PowerPlex~(TM) 16体系在中国人群中罕见等位基因及其类型

目的 分析PowerPlexTM 16体系基因座在中国人群中的罕见等位基因及其类型。方法 应用PCR-STR和DNA序列分析技术,对4650个无关个体在15个STR基因座中的罕见等位基因进行检测。结果 在PowerPlexTM16体系中的D7S820、D16S539、Penta E基因座,检测到2种类型的罕见等位基因,而TH01、D21S11、D5S818、D13S317、Penta D、D8S1179、TPOX、FGA基因座检测出1种类型。其等位基因频率均较低(0.215‰-7.097‰)。结论 超出ladder范围的罕见等位基因序列比相邻等位基因增加(或减少)1个或数个重复单位,因碱基的插入或缺失的罕见等位基因出现在两等位基因之间。     

DNATyper^TM15试剂盒的确证试验

目的测试DNATyper^TM15试剂盒的技术性能指标，评估其法医学应用能力。方法制定测试方案，从方法学验证、灵敏度、混合样本、批次间试剂稳定性及批量样本测试、DNA提取方法适应性测试、各类常见检材的测试、稳定性测试等8个方面进行测试。并与Identifiler^TM PowerPlex16剂盒进行比较。结果DNA Typer TM15试剂盒灵敏度较高，批次间性能稳定，对各类案件检材和DNA提取方法具有较好的适应性，具有检验混合DNA样本检测的能力。结论DNA Typer TM15在上述性能指标等方面已经达到国际同类产品的技术水平，可用于法庭科学的检案与建库。     

Allele frequencies of sixteen STRs in the population of Northern Portugal

Allele frequencies of sixteen autossomal short tandem repeats (STRs), D3S1358, VWA, D16S539, D8S1179, D21S11, D18S51, TH01, FGA, D5S818, D13S317, D7S820, TPOX, CSF1PO, Penta D, Penta E (included in the PowerPlex 16 kit), and the SE33 (PowerPlex ES Monoplex System SE33) were determined in a sample of 200 healthy unrelated individuals from the north of Portugal.     

用新设计引物调查武汉汉族Penta D和Penta E基因座遗传多态性

目的　研究PentaD和PentaE基因座分型引物设计 ,调查PentaD和PentaE基因座在武汉汉族人群中的遗传多态性。方法　用重新设计的PentaD和PentaE基因座分型引物 ,采用热启动PCR和PAGE技术对 2 81名武汉地区汉族无关个体进行分型调查 ,并将其分型结果与Promega公司的PowerPlexTM16系统荧光标记复合扩增试剂盒分型结果进行比较。结果　新设计引物扩增产物的片段大小范围分别为 15 3～ 198bp和 10 7～ 2 12bp ,其分型结果与PowerPlexTM16系统的分型结果完全一致 ,且用银染法检测的灵敏度显著提高 (由 0 5ng提高到 0 2ng)。PentaD和PentaE基因座在武汉汉族群体分别检出 10个和 2 1个等位基因 ,其基因型频率分布均符合Hardy Weinberg平衡。家系调查证实了其等位基因的传递符合孟德尔遗传规律。两基因座的个体识别能力 (DP)分别为 0 92 62、 0 9860 ,非父排除率 (PE)分别为 0 665 1、 0 83 2 5。结论　新设计引物用于PentaD和PentaE基因座的分型检测准确可靠 ,两基因座多态性程度高 ,在法医学个人识别和亲子鉴定中具有使用价值。     

Validation of the PowerPlex 1.1 loci for use in human identification

STR typing is now the favored method of DNA analysis for the purposes of human identification in the forensic community. The Forensic Services Division of the Detroit Police Department has completed its validation of the PowerPlex 1.1 loci (CSF1PO, TPOX, THO1, vWA, D16S539, D7S820, D13S317, and D5S818) for use in forensic casework. Detroit Metro Area Red Cross samples were typed from each of five racial/ethnic groups--the Hispanic, Caucasian, African American, Asian, and American Indian populations--and allele and genotype frequencies were calculated. A rare off-ladder variant (9.1 allele at D7S820) was identified among the database samples. A number of validation studies were performed. DNA was extracted from different substrates and typed as expected, except for the DNA extracted from leather (signal absent from the D16S539, D7S820, D13S317, CSF1PO, and TPOX loci) and from dirt (no PCR product generated). The minor contributor in the mixture study (250 pg input DNA) was facile to discern. The Concordance study, the variety of fluids from the same individual, and NIST standards studies all produced the expected results. Finally, STR data confirmed previous DNA typing results from adjudicated casework samples.     

Population data for 11 STR loci in northeast China Han

Allele frequencies for the nine tetrameric short tandem repeats (STR) loci D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, and D7S820 (AmpFlSTR Profiler Plus PCR amplification kit, PE Applied Biosystems) and two pentameric STR loci Penta D and Penta E (PowerPlex 16 system, Promega Corporation) were determined in a population sample of unrelated China Han.     

Allele frequencies for 15 short tandem repeat loci in a representative sample of Bosnians and Herzegovinians

Allele frequencies for the 15 STR loci (D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX, FGA) included in the PowerPlex 16 kit were obtained from a multiethnic sample of 100 unrelated individuals born in Bosnia and Herzegovina.     

Allele frequencies for 15 STR loci in Van-Ağri districts of the Eastern Anatolia region of Turkey

Allele frequencies of 13 tetrameric short tandem repeat (STR) loci (D3S1358, TH01, D21S11, D18S51, D5S818, D13S317, D7S820, D16S539, CSF1PO, vWA, D8S1179, TPOX, FGA) and 2 pentameric short tandem repeat loci (Penta E and Penta D) included in the PowerPlex 16 kit were obtained from a sample of 116 unrelated individuals in Van-A?ri districts of the Eastern Anatolia region of Turkey. The expected performance of these loci for personal identification and paternity testing in this population was estimated.     

Characterization and validation studies of powerPlex 2.1, a nine-locus short tandem repeat (STR) multiplex system and penta D monoplex

In order to increase the power of discrimination for human identification purposes, a nine-locus short tandem repeat (STR) multiplex, the GenePrint PowerPlex 2.1 system (PowerPlex 2.1) developed by Promega Corporation and a separate pentanucleotide-repeat locus, Penta D, were tested. This megaplex system includes the highly polymorphic loci FGA, TPOX, D8S1179, vWA, Penta E, D18S51, D21S11, TH01, and D3S1358 and may be used in combination with the eight-locus STR multiplex, the GenePrint PowerPlex 1.1 system (PowerPlex 1.1) that has been previously developed. Three of the loci, TPOX, TH01 and vWA, have been included in both systems for quality control purposes. As with PowerPlex 1.1, PowerPlex 2.1 is also based on a two-color detection of fluorescent-labeled DNA products amplified by polymerase chain reaction (PCR) and provides a valuable tool for accurate and rapid allele determination. The primer sequences used in the PowerPlex 2.1/Penta D system are also presented in this report. To meet the "Quality Assurance Standards for Forensic DNA Testing Laboratories" (FBI), we tested the efficiency and reproducibility of the PowerPlex 2.1/PentaD system by several validation studies that were conducted as a joint project among seven laboratories. Validation tests included concordance studies, sensitivity, and species specificity determination, as well as performance in forensic and environmentally impacted samples. The results produced from these tests demonstrated the consistency and reliability of the PowerPlex 2.1/Penta D system.     

Detection of a primer-binding site polymorphism for the STR locus D16S539 using the Powerplex 1.1 system and validation of a degenerate primer to correct for the polymorphism

Quality assurance samples submitted from the NCSBI as part of a contract with TBTG to outsource DNA Database samples showed unexpected discrepancies for the locus D16S539 when all other loci yielded identical results. Discrepancies observed included allele drop out and an imbalance in sister alleles with samples returned from TBTG. This led to a comprehensive review of the technical procedures used between the two laboratories to determine the cause of the discrepancies noted for the locus D16S539, since both laboratories were using the PowerPlex 1.1 typing kit from the Promega Corporation. The NCSBI and the TBTG utilize different extraction methods (organic extraction vs. FTA) and amplification conditions (AmpliTaq vs AmpliTaq Gold), respectively, so the exact cause of discrepancy observed was not immediately apparent. Experiments at the NCSBI associated the observed allele drop out and the imbalance of the sister alleles with the use of AmpliTaq Gold and a hot start procedure. Sequencing data revealed that a point mutation resides on the D16S539 primer-binding site that reaches polymorphic levels in African-American populations. This led to the development of a degenerate primer by the Promega Corporation to detect "missing" alleles when AmpliTaq Gold is used. The degenerate primer was then thoroughly tested to show its efficacy in detecting the "true" D16S539 profile when used.     

STRs data for the loci D3S1385, vWA,FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820 from Córdoba (Argentina)

Allele and genotype frequencies for nine STRs loci included in the AmpFlSTR Profiler Plus kit (D3S1385, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820), were determined from urban and countryside population of Córdoba (Argentina). All loci meet the Hardy-Weinberg expectation, and there is little evidence for alleles association between these nine loci. The results demonstrate that these loci can be useful for databasing purposes in human identification and parentage testing in the population of Córdoba (Argentina).     

武汉汉族人群STR基因座D3S1358、D13S317、D12S391的多态性研究

目的　调查中国武汉地区汉族人群STR基因座—D3S1 358、D1 3S31 7、D1 2S391基因频率分布和群体遗传数据。方法　从 2 0 8个汉族无关个体收集血液标本 ,应用PCR技术及聚丙烯酰胺凝胶垂直板电泳对D3S1 358、D1 3S31 7和D1 2S391基因座分型。结果　D3S1 358检出 7个等位基因和 4 1个基因型。三基因座基因型分布符合Hardy-Weinberg平衡。观察 2 31次减数分裂均未发现突变基因。另外 ,调查结果计算显示D3S1 358、D1 3S31 7和D1 2S391基因座的杂合度 (H)分别为 0 70 98、 0 80 56和 0 84 0 0 ;三个人识别能力 (DP)分别为 0 851 6、 0 9332和 0 952 3;非父排除率 ( pE)分别为 0 4 463、 0 60 1 6和 0 681 8。结论　D3S1 358、D1 3S31 7和D1 2S391基因座在群体遗传学研究和法医学亲子鉴定及个人识别中具有较高实用价值     

多色荧光STR检测试剂盒的研制与验证

目的建立18个基因座的PCR扩增检测试剂盒。方法采用两个多重PCR体系和四色荧光素标记技术,对Amelogenin和17个STR基因座(D3S1358、vWA、FGA、D8S1179、D21S11、D18S51、D5S818、D13S317、D16S539、TH01、TPOX、CSF1PO、D7S820、D2S1338、D19S433、D12S391和D19S253)进行基因型检测,并对其可靠性、稳定性、效能等进行研究。结果通过2个多重PCR扩增体系,可以成功地对各类生物学检材的Amelogenin和17个STR基因座进行检测,且可靠、稳定、高效。结论本研究所研制的试剂盒,是对该18个基因座进行检测的高效、稳定、可靠的新体系。     

测序方法验证12个STR基因座的基因型

目的 用测序方法验证12个STR基因座的基因型.方法 根据各STR基因座的特异性序列,对CSF1PO、FGA、TH01、TPOX、VWA、D5S818、D7S820、D8S1179、D13S317、D16S539、D18S51和D21S11 12个STR基因座设计了PCR引物并对标准品9947A和突变样本进行PCR产物测序.结果 标准品9947A和突变样本的测序结果均与其基因分型结果一致.结论 建立的测序方法准确、灵敏,可以用于STR基因型的确认.     

Locked nucleic acids: Increased trace DNA amplification success with improved primers

Locked nucleic acids (LNAs) are a conformationally restricted DNA analog, which can be incorporated into oligonucleotides to increase binding strength. To investigate if LNAs increase amplification success for trace DNA samples in a forensic context, primer sequences for four routinely used STR loci (FGA, D7S820, D13S317 and D18S51) have been altered to include LNA bases. The LNA modified primers display a broader tolerance to a range of reaction conditions compared to unmodified DNA primers, with higher T_ms giving increased specificity. Increased peak heights, improved peak height ratios and decreased template requirements were seen with LNA primers. The increased amplification success of LNA primers, and broader range of optimal reaction conditions, suggest that using LNA primers for multiplex STR genotyping assays could be highly beneficial for trace DNA genotyping.     

Concordance study on population database samples using the PowerPlex 16 kit and AmpFlSTR Profiler Plus kit and AmpFlSTR COfiler kit

Over 500 population database samples comprising African Americans, Bahamians, and Southwestern Hispanics were typed using the PowerPlex 16 and the Profiler Plus COfiler kits. There was only one sample in which a typing difference was observed. An FGA heterozygote profile was observed using the PowerPlex 16 primers, and a single allele FGA profile was observed using Profiler Plus primers. Thus, the extant data suggest that the primers used in the PowerPlex 16, Profiler Plus, and COfiler kits are reliable for typing reference samples destined for use in CODIS. In addition, African American, Bahamian, and Southwestern Hispanic databases have been established for the STR loci Penta D and Penta E. Both loci are highly polymorphic. The application of the product rule is valid for estimating the rarity of a multiple loci profile consisting of these two and the 13 core STR loci.     

Allele frequencies and genetic data of 16 highly polymorphic loci in Koreans

Allele and genotype frequencies for the 15 STR loci (FGA, vWA, MBP-L, MBP-H, HumTh01, D3S1358, D3S2406, D5S818, D7S820, D8S1179, D13S317, D18S51, D19S253, and D21S11) and two VNTR loci (D1S80 and D17S5) in a sample of unrelated Koreans were determined.