A multiplex allele-specific primer extension assay for forensically informative SNPs distributed throughout the mitochondrial genome

The typing of single nucleotide polymorphisms (SNPs) located throughout the mitochondrial genome (mtGenome) can help resolve individuals with an identical HV1/HV2 mitotype. A set of 11 SNPs selected for distinguishing individuals of the most common Caucasian HV1/HV2 mitotype were incorporated in an allele specific primer extension assay. The assay was optimized for multiplex detection of SNPs at positions 3010, 4793, 10211, 5004, 7028, 7202, 16519, 12858, 4580, 477 and 14470 in the mtGenome. Primers were designed to allow for simultaneous PCR amplification of 11 unique regions in the mtGenome and subsequent primer extension. By enzymatically incorporating fluorescently labeled dideoxynucleotides (ddNTPs) onto the 3 end of the extension primer, detection can be accomplished with a capillary-based electrophoresis (CE) platform common in most forensic laboratories. The electrophoretic mobility for the extension primers was compared in denaturing POP4 and POP6 CE running buffers. Empirical adjustment of extension primer concentrations resulted in even signal intensity for the 11 loci probed. We demonstrate that the assay performs well for heteroplasmy and mixture detection, and for typical mtDNA casework samples with highly degraded DNA.Official disclaimers. Certain commercial equipment, instruments and materials are identified in order to specify experimental procedures as completely as possible. In no case does such identification imply a recommendation or endorsement by the National Institute of Standards and Technology nor does it imply that any of the materials, instruments or equipment identified are necessarily the best available for the purpose. The opinions and assertions contained herein are solely those of the authors and are not to be construed as official or as views of the U.S. Department of Defense, the U.S. Department of the Army, or the U.S. Department of Justice.Sources of support. The National Institute of Justice (NIJ) funded the work described here through an interagency agreement with the NIST Office of Law Enforcement Standards. This work was also supported by the National Institute of Justice grant 2000-1J-CX-K010 to T.J.P.     

Development and validation of a multiplex insertion/deletion marker panel,SifaInDel 45plex system

In addition to commonly used short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs), insertion and deletion polymorphisms (InDels) have considerable potential in the field of forensic genetics because they combine desirable characteristics of both STRs and SNPs. In the present study, the SifaInDel 45plex system was designed to amplify 45 InDel markers, including 27 autosomal InDels (A-InDels), 16 X chromosome InDels (X-InDels) and two Y chromosome InDels (Y-InDels), simultaneously in a single PCR procedure and then detect products by capillary electrophoresis (CE). We also optimized the PCR conditions for the novel panel and performed several validation studies including repeatability/reproducibility, concordance, accuracy, sensitivity, stability, species specificity and population genetics.The results confirmed that full profiles could be obtained from ≥62.5 pg of input DNA and from a series of challenging samples encountered in routine casework. The SifaInDel 45plex panel could tolerate different concentrations of inhibitors, such as ≤50 μM hematin, ≤20 ng/μL nigrosine and ≤8000 ng/μL urea. In a population investigation, for the 27 A-InDels, the combined power of discrimination (CPD) exceeded 0.999999, and the combined power of exclusion in duos (CPE_D) and trios (CPE_T) was 0.955118 and 0.997754, respectively. For the 16 X-InDels, the combined PD_Male and PD_Female was computed as 0.999845 and 0.999998, respectively, and the combined mean exclusion chance in father/daughter or mother/son duos (MEC_Duo) and mean exclusion chance in standard trios involving daughters (MEC_Trio) was 0.976220 and 0.998163, respectively. In addition, the two Y-InDels could play a role in correctly determining gender. Overall, the established SifaInDel 45plex panel is a well-performing, reliable and robust multiplex system that stands out for combining a considerable number of A-indels, X-indels and Y-indels based on a CE platform. The population study results also demonstrated that the SifaInDel 45plex panel could be a valid complementary approach for human identification and complex kinship analysis.     

Population genetics of nine short tandem repeat (STR) loci – DNA typing using the AmpFlSTR Profiler PCR amplification kit

Frequency data for nine short tandem repeat (STR) loci were collected from 130 unrelated Caucasians from North Bavaria using the AmpFlSTR Profiler multiplex system. The loci D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, D7S820 and the sex test amelogenin were investigated. Allele frequencies, rates of heterozygosity and the discrimination power of the combined systems were calculated by statistical analysis. Except for D5S818 all loci met Hardy-Weinberg expectations. Received: 27 August 1998 / Received in revised form: 28 December 1998     

Semi-automatic DNA profiling in a Hungarian Romany population using the STR loci HumVWFA31, HumTH01, HumTPOX, and HumCSF1PO

A population study of Hungarian Romanies was carried out for the STR loci HumVWFA31, HumTH01, HumTPOX, and HumCSF1PO. After multiplex PCR amplification semi-automatic DNA profiling was performed using an ALF DNA sequencer. At the loci investigated there was little and no evidence for departures from Hardy-Weinberg expectations and linkage equilibrium, respectively. The allele sizing accuracy of the ALF DNA sequencer was increased to a high level (99.97% on average) by applying external and internal markers. Allele frequency distributions of the STR loci, with one exception, were significantly different between the Romany and other Hungarian population databases. On the other hand, however, only small differences in frequencies of individual phenotypes were found. Received: 30 December 1996 / Received in revised form: 11 March 1997     

Population genetics of the STRs vWA, D3S1358 and FGA in the Pomerania-Kujawy region of Poland

This paper presents the results of a Polish population study (n = 210) for the three STR loci vWA, D3S1358 and FGA analysed using the multiplex PCR system AmpflSTR Blue. The allele distributions were in accordance with Hardy-Weinberg expectations. The combined mean exclusion chance, mean paternity index and power of discrimination for the three loci were MEC = 0.96055, MPI = 127.1295 and PD = 0.99986. This demonstrates that these systems are valuable tools for forensic identification and paternity testing. Received: 24 August 1998 / Received in revised form: 19 January 1999     

Ribosomal DNA as target for the assessment of DNA degradation of human and canine DNA

The assessment of DNA amount and DNA integrity can support forensic DNA analysis, in particular of problematic traces such as single telogen hairs where STR typing success is often hampered by low amounts and strong degradation of nuclear DNA. Common strategies consist of quantitative polymerase chain reaction (qPCR)-based analysis of the abundance of a short versus a long nuclear amplicon, the latter prone to DNA degradation. To increase sensitivity, commercial qPCR solutions rest on amplification of multi-copy DNA sequences. Here we show that ribosomal DNA (rDNA) sequences are well suited for the same purpose. Because rDNA sequences are present in high copy number in most eukaryotic species, qPCR strategies can easily be adapted to non-human species. In this paper, we establish qPCR-based assays for human or dog DNA, respectively, which allow for sensitive analysis of DNA amounts and DNA degradation. We show that the human system can be applied to DNA of single telogen hairs, where STR typing success correlates with measured amounts and integrity of the DNA. By adapting the system to dog rDNA sequences we found that single telogen dog hairs often displayed less DNA degradation than human telogen hairs, in most cases allowing for successful STR typing. Thus, qPCR-based analysis of rDNA represents a cost-effective, highly sensitive strategy to assess DNA amount and integrity that can be adapted to hairs or other traces from various animal species.     

Extraction strategy for obtaining DNA from bloodstains for PCR amplification and typing of the HLA-DQa gene

Summary A simple, practical approach for the extraction of PCR-amplifiable DNA for the HLA-DQa gene from bloodstains deposited on various substrates is described. DNA from bloodstains is purified using Chelex 100 ion-exchange resin and then amplified. If amplification is not achieved, the extract is washed through a Centricon 100 dialysis/concentration tube. If the second amplification of this extract produces a negative result, the extract is processed with Chelex 100 again. This approach has been found to be reliable, safe, efficient and economical.     

输血传播病毒-DNA聚合酶链方法的建立及应用

目的：建立输血传播病毒（ＴＴＶ）－ＤＮＡ聚合酶链反应方法并应用于新疆地区不同人群ＴＴＶ感染的检测。方法：根据已报道的ＴＴＶ基因痛列（ＤＤＢＪ序列号：ＡＢ００８３９４）,通过引物设计软件ＳＱＮＣＥ和ＯＬＩＧＯ在其ＯＲＦ１区设计一对ＰＣＲ引物,扩增产生一个３１５ｂｐ的扩增片段,产物经ＢｇⅠⅡ酶切分别产生一个２１９ｂｐ和９６ｂｐ的酶切片段。结果：用建立的ＰＣＲ方法在１５例维存尔族转氨酶升高的非甲－非庚型     

Development and validation of a new STR 25-plex typing system

In this study, a new STR 25-plex typing system, including 23 autosomal STRs (D1S1656, D2S1338, D2S441, D3S1358, D5S818, D6S1043, D7S820, D8S1179, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, CSF1PO, FGA, Penta D, Penta E, TH01, TPOX, vWA) and a Y-STR locus of DYS391 and amelogenin, was developed. The included 24 STRs belonged to the main international DNA databases (CODIS, ISSL, ESS-extended, UCL, GCL and NCIDD) except D6S1043 (specially chosen for Chinese population). Developmental validation indicated that the STR 25-plex typing system was reproducible, accurate, sensitive and robust. The sensitivity testing of the system was such that a full profile was obtainable even with 125 pg of human DNA. Specificity testing was demonstrated by the lack of cross-reactivity with a variety of commonly encountered animal species and microbial pool. For the stability testing, full profiles can been obtained with humic acid concentration ≤ 60 ng/μL and hematin < 500 μM. Also, this multiplex system is suitable for mixture study. All of the minor alleles were called for ratios of 1:1, 1:3 and 3:1 of the mixture with the system. In addition, the whole PCR amplification can finish within 1 h, making the system suitable for fast-detection. For the forensic evaluation of the multiplex system, 23 autosomal STRs included followed the Hardy–Weinberg equilibrium. A total of 268 alleles were detected for the 23 autosomal STR loci among 200 individuals. Since 23 autosomal STRs were independent from each other, CMEC_duo was 0.99999916563607 and CMEC_tri was 0.99999999986525. All the forensic efficiency parameters demonstrated that this multiplex system is highly polymorphic and informative in the Han population of China.     

Integrated sample cleanup and capillary array electrophoresis microchip for forensic short tandem repeat analysis

A twelve-lane capillary array electrophoresis (CAE) microsystem is developed that utilizes an efficient inline capture injection process together with the classical radial microfabricated capillary array electrophoresis (μCAE) format for high-sensitivity forensic short tandem repeat (STR) analysis. Biotin-labeled 9-plex STR amplicons are captured in a photopolymerized gel plug via the strong binding of streptavidin and biotin, followed by efficient washing and thermal release for CE separation. The analysis of 12 STR samples is completed in 30 min without any manual process intervention. A comparison between capture inline injection and conventional cross injection demonstrated at least 10-fold improvement in sensitivity. The limit-of-detection of the capture-CAE system was determined to be 35 haploid copies (17–18 diploid copies) of input DNA; this detection limit approaches the theoretical limits calculated using Poisson statistics and the spectral sensitivity of the instrument. To evaluate the capability of this microsystem for low-copy-number (LCN) analysis, three touch evidence samples recovered from unfired bullet cartridges in a pistol submerged in water for an hour were successfully analyzed, providing 53, 71, and 59% of the DNA profile. The high-throughput capture-CAE microsystem presented here provides a more robust and more sensitive platform for conventional as well as LCN and degraded DNA analysis.     

Hungarian population data on six STR loci — HUMVWFA31, HUMTH01, HUMCSF1PO,HUMFES/FPS,HUMTPOX, and HUMHPRTB —derived using multiplex PCR amplification and manual typing

We present a Hungarian population study for six tetrameric short tandem repeat (STR) loci employing multiplex PCR amplification, electrophoresis of the PCR products in DNA sequencing gels and subsequent detection of allelic fragments by silver staining. The loci were HUMVWFA31, HUMTH01, HUMCSF1PO, HUMFES/FPS, HUMTPOX, and HUMHPRTB. All loci met Hardy-Weinberg expectations in the examined Hungarian Caucasian population sample (N = 223 individuals). In addition, there was no evidence for association of alleles among the five autosomal loci HUMVWFA31, HUMTH01, HUMCSFIPO, HUMFES/FPS, and HUMTPOX.     

Sequential multiplex amplification (SMA) of genetic loci: A method for recovering template DNA for subsequent analyses of additional loci

A method called Sequential Multiplex Amplification (SMA) has been developed whereby a limited amount of DNA extracted from a sample can be reutilized for several single polymerase chain reaction (PCR) amplifications. The method involves recovery of genomic template DNA by microfiltration of PCR-amplified samples. Up to 5 different loci have been typed, each in a single system PCR-based assay, beginning with a test quantity of 5 ng template DNA. Genotypes of the DNA donors were compared with those obtained from individual amplifications and shown to be identical. This could be a useful technique for typing a number of loci from a limited amount of DNa and to recover template DNA from samples previously subjected to PCR. Obviously, when small quantities of template DNA are available, this technique can prove quite useful.     

The art of traditional native PAGE: The APLP 48-ID assay for human identification

When full STR profiles cannot be obtained, further DNA analyses targeting single nucleotide polymorphisms (SNPs) may occasionally yield valuable information. Although the discrimination power of each SNP is relatively low, combined analysis of many SNPs can improve the personal identification ability to a level as high as that of commercial STR typing kits. In this study, we developed a new SNP typing method, named the amplified-product length polymorphism (APLP) 48-ID assay, for genotyping of 47 autosomal SNPs and two X and Y chromosomal markers for sex typing. Forty-seven SNPs were selected from all 22 autosomes, showing high diversity in European, Nigerian, Han Chinese, and Japanese population in the HapMap data. PCR primers were designed to generate amplicons 40–100 bp in length to increase the robustness of the PCR.The APLP 48-ID assay consisted of four independent PCR reactions followed by electrophoretic run on four lanes in a polyacrylamide gel. Complete profiles were obtained when more than 1.2 ng of DNA was used. We applied this assay for genotyping of 236 Japanese individuals. The random matching probability was 3.3E-20, and the power of exclusion was greater than 0.9999999. This method is a rapid, robust, and cost-effective approach for human identification and paternity testing.     

A multiplex PCR for 4 X chromosome STR markers and population data from Beijing Han ethnic group

STR multiplex is a practical and simple method to obtain large amounts of important information in forensic and population genetic studies. The present work describes a new multiplex system that allows the simultaneous analysis of 4 X-STR markers, namely DXS9902, DXS6800, DXS6799 and DXS7132, as the tool of approach for X-STR studies. In addition, this work presents the genotyping results obtained for a sample 400 individuals (200 males and 200 females) from Beijing Han ethnic group in China.     

Development of a multiplex assay for detection of autosomal and Y-chromosomal STRs,assessment of the degradation state of mitochondrial DNA and presence of mitochondrial length heteroplasmies

The current focus in most routine forensic casework is detection of autosomal or gonosomal Short Tandem Repeats (STRs). With increasing degradation, STR analysis tends to be less successful up to complete failure. For challenging samples such as telogen hair roots and shafts, touch DNA samples or skeletal remains, mitochondrial DNA (mtDNA) analysis provides a powerful tool. Determination of DNA quantity is an important part in the casework workflow. Several ready-to-use kits are commercially available for nuclear DNA targets. However, quantification of mtDNA targets requires the establishment of an in-house method. Some assays even contain assessment of degradation, which alleviates the choice of target enrichment for sequencing through medium or small amplicons. As Sanger-type Sequencing (STS) still remains the golden standard in many laboratories, identification of heteroplasmies in C-tract regions prior to the sequencing reaction is advantageous. Firstly, primer selection can be expanded with primers binding near the C-tract and secondly, determination of the dominant variant is straightforward. All those quantity (nuclear and mtDNA) and quality (degradation and length heteroplasmies) evaluations usually require at least two separate reactions. Therefore, the aim of this project was the combination of all these targets in one multiplex assay using capillary electrophoresis to spare valuable sample extract. Amplification of representative autosomal and Y-chromosomal STRs allows estimate of success of (Y-)STR analysis. Simultaneously, five length heteroplasmies in the mitochondrial control region are targeted as well as three conservative regions of differing fragment lengths for assessment of the mitochondrial degradation state. Based on the outcome of this assay, forensic examiners can decide if STR analysis may be suitable. In case of absent STR peaks, appropriate proceeding of mtDNA sequencing can be determined.     

A new method for ABO genotyping using a multiplex single-base primer extension reaction and its application to forensic casework samples

We developed a new method for ABO genotyping using a multiplex single-base primer extension reaction. The method allows for the simultaneous detection of six SNP sites in the ABO gene (nt 261, 297, 681, 703, 802, and 803) and the determination of ABO genotypes from their combinations. It enabled ABO genotyping of all samples of peripheral blood DNA extracted from 103 Japanese individuals, and had a highly satisfactory detection sensitivity being capable of genotyping 0.1 ng of genomic DNA. Using this method, we were able to determine ABO genotypes of minute stain samples, heated bloodstains, aged bloodstains and mixed samples. Experiments with samples from 26 animal species and bacterial samples to test the species-specificity of the method showed that genotyping was possible in the chimpanzee and gorilla, but their genotypes were extremely rare in humans. In addition, we applied this method to casework samples, and successfully determined ABO genotypes of bones, teeth, muscles, organs, nails, and semen-contaminated vaginal fluid in which ABO grouping by conventional serological techniques was not possible. This new method enables the sensitive, simultaneous detection of six SNP sites in the ABO gene by two specific reactions, i.e. PCR and a primer extension reaction. Therefore, it holds promise as an effective method of ABO genotyping particularly for forensic samples.     

A 16-plex Y-SNP typing system based on allele-specific PCR for the genotyping of Chinese Y-chromosomal haplogroups

Y-chromosomal SNP (Y-SNP), with its stable inheritance and low mutation, can provide Supplementary information in forensic investigation. While commonly used Y-chromosomal STR haplotypes show their limitations, typing of Y-SNP would become a powerful complement. In this study, a 16-plex Y-SNP typing system based on allele-specific PCR (AS-PCR) was developed to discriminate four dominant Y-chromosomal haplogroups (C-M130, D-CTS3946, N-M231, and O-M175) and 12 predominant sub-haplogroups of O-M175 (O1a-M119, O1a1a1a-CTS3265, O1b-M268, O1b1a2-Page59, O2-M122, O2a1-L127.1, O2a1b-F240, O2a1b1a1-CTS5820, O2a2-P201, O2a2b1a1-M177, O2a2b1a1a1a-Y17728, O2a2b1a2-F114). A series of experimental validation studies including sensitivity, species specificity, male-female mixture and inhibition were performed. The discrimination of the typing system was preliminarily proved with a haplogroup diversity of 0.9239. Altogether, the Y-SNP typing system based on AS-PCR should be capable of distinguishing China’s dominant Y-chromosomal haplogroups in a rapid and reliable manner, thus can be employed as a useful complement in forensic casework.     

MiniX-STR multiplex system population study in Japan and application to degraded DNA analysis

We sought to evaluate a more effective system for analyzing X-chromosomal short tandem repeats (X-STRs) in highly degraded DNA. To generate smaller amplicon lengths, we designed new polymerase chain reaction (PCR) primers for DXS7423, DXS6789, DXS101, GATA31E08, DXS8378, DXS7133, DXS7424, and GATA165B12 at X-linked short tandem repeat (STR) loci, devising two miniX-multiplex PCR systems. Among 333 Japanese individuals, these X-linked loci were detected in amplification products ranging in length from 76 to 169 bp, and statistical analyses of the eight loci indicated a high usefulness for the Japanese forensic practice. Results of tests on highly degraded DNA indicated the miniX-STR multiplex strategies to be an effective system for analyzing degraded DNA. We conclude that analysis by the current miniX-STR multiplex systems offers high effectiveness for personal identification from degraded DNA samples.     

弥漫大B细胞淋巴瘤患者miR-125表达水平与临床病理及预后的关系分析

目的 分析弥漫大B细胞淋巴瘤(Diffuse Large B-cell Lymphoma,DLBCL)患者微小RNA-125(microRNA-125,miR-125)表达水平与临床病理参数及预后的关系.方法 回顾性分析2015年3月-2017年3月四川大学华西医院血液内科收治的148例DLBCL患者的临床资料,列为D...