Large-scale concordance study for 16 autosomal STRs analyzed with PowerPlex ESI17 and NGM SElect

This study aimed at identifying the frequency of kit-dependent discordances and genetic specialties in STR DNA typing, which is particularly important for the interpretation of DNA profiles as well as national and international database searches. We analyzed a total of 27′510 buccal swabs with the PowerPlex ESI 17 and NGM SElect amplification kits and documented discordances and other anomalies. We found kit-dependent full dropouts to be the most frequent events, most of which were associated with the NGM SElect kit. The total kit-dependent discordance rate determined in this study amounts to 0.74%. With this dataset, we also provide dropout rates, which can be used to estimate silent allele frequencies for 16 common STR loci amplified with the PowerPlex ESI17 and NGM SElect amplification kits.     

Comparison of DNA typing using AmpFlSTR Yfiler and PowerPlex Y System,for specimens subject to very long storage

We performed DNA typing from blood stains stored at room temperature for 22–30 years, using AmpFlSTR Yfiler PCR amplification Kit and PowerPlex Y System to extract and amplify the DNA and performing electrophoresis with an ABI 310 Genetic Analyzer. We identified alleles using GeneMapper ID v3.2.1 software. We found that long-term storage tended to reduce the number of detectable loci in the blood stains and that it was easier to detect the loci of smaller amplicons than larger amplicons.     

Rapid and high-throughput forensic short tandem repeat typing using a 96-lane microfabricated capillary array electrophoresis microdevice

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.     

PowerPlex16 HS系统直接扩增法检测肋软骨

目的检验PowerPlex16HS直接扩增系统对软骨的有效性。方法采用PowerPlex16HS复合扩增系统对10例腐败尸体的肋软骨进行直接扩增检验。结果所检验肋软骨都获得了完整遗传图谱,检测成功率为100%。结论 PowerPlex16HS系统直接扩增法能够应用于肋软骨的DNA分型检验。     

PowerPlex21 系统在亲子鉴定中的应用评估

目的评估PowerPlex21系统20个STR基因座在亲子鉴定中的检验能力。方法用PowerPlex21系统检测1 704例亲子鉴定,评估该系统在亲子鉴定中的排除能力和突变率。结果采用PowerPlex21系统,累积非父排除率和累积个体识别力均大于0.999 999 999 999 999 999 999 999 999 999。1704例亲子鉴定中有265例排除亲子关系,最常见为8~10个基因座排除;44例表现为1个STR基因座突变。结论 PowerPlex21系统用于亲子鉴定是高效的。     

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.     

The distribution of Y-chromosome STRs in Dominican population

We have studied the distribution of Y-chromosome STRs and established a database within population samples from Dominican Republic by analyzing male-specific markers. Laboratorio Clinico Lic Patria Rivas collected in the population samples and this population is truly representative of the entire country. We analyzed 12 Y-STRs loci included in PowerPlex Y (Promega Corporation).     

Internal validation study of the PowerPlex® Y23 system

The PowerPlex Y23 System is a 23-loci, 5-color Y-STR multiplex designed for genotyping forensic casework samples, database samples and paternity samples. The kit contains: all 12 loci in the current PowerPlex Y System, the additional 5 loci found in AmpFlSTR Y-filer, plus 6 new loci. An internal validation study of the PowerPlex Y23 kit was therefore conducted including the following aspects: sensitivity, mixture studies of male–male and female–male DNA, performance with simulated inhibition and stutter calculations. 100 Caucasians living in Switzerland were also typed using the PowerPlex Y23 kit.     

D5S818 Typing Discrepancy Between PowerPlex® Fusion and Other STR Kits Including GlobalFiler® Caused by a One‐base Deletion in 31 Nucleotides Upstream of the Repeat Region

Short tandem repeat (STR) typing is widely used in forensic investigation. When the same DNA sample is analyzed with different STR typing kits, a typing discrepancy is occasionally observed. In this study, we examined the cause of a typing discrepancy in a sample at D5S818 locus. This sample was designated as 10, 12 using Identifiler^®, Identifiler^® Plus, GlobalFiler^®, PowerPlex^® 16HS, and PowerPlex^® 18D, but as 9.3, 12 using PowerPlex^® Fusion. Sequencing results indicated that the shorter allele in the sample had a deletion (U31Tdel) at 31 nucleotides upstream of the repeat region (AGAT)₁₀. This deletion was located in the binding site of the published D5S818 forward primer in PowerPlex^® 16 and was only 9 and 11 nucleotides downstream of our estimated 5′ end position of D5S818 forward primer in GlobalFiler^® and PowerPlex^® 18D, respectively. We also examined the effect of primer length on the heterozygous peak balance in this sample.