Search results for "Forensic"
showing 10 items of 1701 documents
Forensic validation of the SNPforID 52-plex assay.
2007
The advantages of single nucleotide polymorphism (SNP) typing in forensic genetics are well known and include a wider choice of high-throughput typing platforms, lower mutation rates, and improved analysis of degraded samples. However, if SNPs are to become a realistic supplement to current short tandem repeat (STR) typing methods, they must be shown to successfully and reliably analyse the challenging samples commonly encountered in casework situations. The European SNPforID consortium, supported by the EU GROWTH programme, has developed a multiplex of 52 SNPs for forensic analysis, with the amplification of all 52 loci in a single reaction followed by two single base extension (SBE) react…
Forensic typing of autosomal SNPs with a 29 SNP-multiplex--results of a collaborative EDNAP exercise.
2008
We report the results of an inter-laboratory exercise on typing of autosomal single nucleotide polymorphisms (SNP) for forensic genetic investigations in crime cases. The European DNA Profiling Group (EDNAP), a working group under the International Society for Forensic Genetics (ISFG), organised the exercise. A total of 11 European and one US forensic genetic laboratories tested a subset of a 52 SNP-multiplex PCR kit developed by the SNPforID consortium. The 52 SNP-multiplex kit amplifies 52 DNA fragments with 52 autosomal SNP loci in one multiplex PCR. The 52 SNPs are detected in two separate single base extension (SBE) multiplex reactions with 29 and 23 SNPs, respectively, using SNaPshot …
New alleles and mutational events at 14 STR loci from different German populations.
2007
The molecular origin of DNA mutations and the mutation rates were analyzed at 14 short tandem repeat (STR) loci with samples from trio cases derived from 10 different German population samples. STR loci comprised of D2S1360, D3S1744, D4S2366, D5S2500, D6S474, D7S1517, D8S1132, D10S2325, D12S391, D18S51, D19S246, D20S480, D21S226, and D22S689. In a total of 488 meioses, 16 isolated genetic inconsistencies in 8 different STRs were observed, whereas no mutations were found at the other loci. The data of five mutations suggested the presence of silent or null alleles due to sequence variation in primer binding site. This could be confirmed for four suspected cases by the use of alternative prim…
Forensic validation of Y-chromosome STR polymorphisms in Italy: the GE.F.I. collaborative database
2003
Abstract Haplotype data of 1176 Italian males from 10 regions were obtained as a part of a collaborative validation exercise. Individual data are available at http://www.gefi-forensicDNA.it .
A sensitive issue: Pyrosequencing as a valuable forensic SNP typing platform
2006
Analysing minute amounts of DNA is a routine challenge in forensics in part due to the poor sensitivity of an instrument and its inability to detect results from forensic samples. In this study, the sensitivity of the Pyrosequencing method is investigated using varying concentrations of DNA and five autosomal single nucleotide polymorphisms in singleplex on both available instrument models; the PSQ™ 96MA and PSQ™ HS 96A. A detailed comparison of the two models was completed while establishing a lower limit of detection on both instruments to give results supporting the use of Pyrosequencing as a valuable forensic SNP typing platform. © 2005 Elsevier B.V. All rights reserved.
Validation and casework testing of the BioPlex-11 for STR typing of telogen hair roots.
2005
A new STR typing strategy has been developed allowing the simultaneous amplification and subsequent analysis of 11 polymorphic systems with amplicon sizes smaller than 270 bp. The multiplex amplification reaction includes six STR loci from the European standard set of loci (ESS) for DNA databases (D3S1358, D8S1179, D21S11, THO1, FGA and VWA) as well as four additional STR systems selected for their robustness (D2S1338, D12S391, TPOX and D5S818) together with the sex-specific locus amelogenin. After PCR amplification, the multiplex reaction is splitted into two sets of STR multiplexes by using biotin labelled primers only for one set. Using streptavidin-coated Sepharose beads five STR system…
Report of the European DNA profiling group (EDNAP)-an investigation of the hypervariable STR loci ACTBP2, APOAI1 and D11S554 and the compound loci D1…
1999
This paper describes the results of three collaborative exercises which continues the EDNAP theme to explore whether uniformity of DNA profiling results could be achieved between European laboratories using STRs. In an earlier exercise, complex hypervariable AAAG-repeat STR loci were investigated, but reproducibility was found to be poor because of the variation of techniques used by participating laboratories. In the exercise reported here, an internal allelic ladder composed of ACTBP2 and D11S554 fragments was distributed. This ladder was used to size ACTBP2 analysed by a "singleplex" PCR amplification and D11S554 combined with APOAI1 in a separate "duplex" reaction. Laboratories were ask…
Considerations from the European DNA profiling group (EDNAP) concerning STR nomenclature
1997
(1) The nomenclature of any STR follows from comparison with a control allelic ladder; availability of reference allelic ladders is central to any scheme. The components of an allelic ladder should be sequenced. (2) The DNA commission recommended a nomenclature based upon the number of repeat sequences present in an allele. Whereas this method is suitable for typing simple STRs, complex hypervariable repeats such as ACTBP2 do not conform to a simple repeating structure. We propose that designation of complex STR repeats such as ACTBP2, D11S554 and APOAI1 follows from the size of specific alleles. Because the size is dependant upon the primers utilised, the size is not definitive (it may als…
Results of collaborative study regarding the standardization of the Y-linked STR system DYS385 by the European DNA Profiling (EDNAP) group.
1999
Y-chromosome linked short tandem repeat (STR) loci are inherited as a closely linked haplotype, which appears to remain stable in a given paternal lineage over many generations. In forensic cases, Y-linked STRs are particularly useful for the identification of human remains as well as in rape cases with mixed male/female stain samples. DYS385 is derived from tandemly duplicated segments of the Y chromosome thus giving rise to two fragments of variable length which do not behave like alleles but genotypes. The European DNA Profiling (EDNAP) group has carried out a collaborative exercise among 14 participating laboratories using DYS385 for typing of five unknown bloodstains and a control samp…
Biostatistical basis of individualization and segregation analysis using the multilocus DNA probe MZ 1.3: results of a collaborative study.
1992
A collaborative study using the multilocus minisatellite DNA probe MZ 1.3 was carried out to investigate segregation information, mutation rate, DNA fragment frequencies as well as band sharing characteristics. The fingerprint patterns of 393 children as well as 694 unrelated individuals were analysed after digestion of DNA with the restriction enzyme HinfI. A mutation rate of 1% per meiosis or 0.04% per band was found with a mean number of 26 bands/individual. It was shown that maternal and paternal fragments are inherited in equal proportions. Population frequencies of restriction fragments demonstrated a distribution with increasing frequencies in the small fragment size range below 10 k…