Search results for "Forensic genetic"
showing 10 items of 12 documents
DNA Evidence Uncompromised by Active Oxygen
2010
Currently, forensic sciences can make use of the potential of instrumental analysis techniques to obtain information from the smallest, even invisible, samples. However, as laboratory techniques improve, so too should the procedures applied in the search for and initial testing of clues in order to be equally effective. This requires continuous revision so that those procedures may resolve the problems that samples present. As far as bloodstains are concerned, there are methods available that are recognized as being both highly sensitive and effective. Nevertheless, the marketing of new cleaning products, those that contain active oxygen, has raised doubts about the ability of those procedu…
The molecular characterization of a depurinated trial DNA sample can be a model to understand the reliability of the results in forensic genetics
2014
The role of DNA damage in PCR processivity/fidelity is a relevant topic in molecular investigation of aged/forensic samples. In order to reproduce one of the most common lesions occurring in postmortem tissues, a new protocol based on aqueous hydrolysis of the DNA was developed in vitro. Twenty-five forensic laboratories were then provided with 3.0 μg of a trial sample (TS) exhibiting, in mean, the loss of 1 base of 20, and a molecular weight below 300 bp. Each participating laboratory could freely choose any combination of methods, leading to the quantification and to the definition of the STR profile of the TS, through the documentation of each step of the analytical approaches selected. …
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…
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…
Old meets new: Comparative examination of conventional and innovative RNA-based methods for body fluid identification of laundered seminal fluid stai…
2018
Abstract The knowledge about the type of the body fluid/tissue that contributed to a trace can provide contextual insight into crime scene reconstruction and connect a suspect or a victim to a crime scene. Especially in sexual assault cases, it is important to verify the presence of spermatozoa. Victims often tend to clean their underwear/bedding after a sexual assault. If they later decide to report the crime to the police, in our experience, investigators usually do not send laundered items for DNA examination, since they believe that analysis after washing is no longer promising. As not only the individualization of traces on laundered items could be important in court, but also the type…
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 …
Paternity Testing Commission of the International Society of Forensic Genetics: recommendations on genetic investigations in paternity cases
2003
The International Society for Forensic Genetics (ISFG) has established a Paternity Testing Commission (PTC) with the purpose of formulating international recommendations concerning genetic investigations in paternity testing. The PTC recommends that paternity testing be performed in accordance with the ISO 17025 standards. The ISO 17025 standards are general standards for testing laboratories and the PTC offers explanations and recommendations concerning selected areas of special importance to paternity testing. # 2002 Elsevier Science Ireland Ltd. All rights reserved.
Second generation sequencing of three STRs D3S1358, D12S391 and D21S11 in Danes and a new nomenclature for sequenced STR alleles
2014
Second generation sequencing (SGS) may revolutionize the field of forensic STR typing. Two of the essential requirements for implementation of an SGS based approach for forensic investigations are (1) establishment of adequate frequency databases and (2) adoption of a new STR nomenclature. We report the STR sequences and allele frequencies of three STR loci: D3S1358, D12S391 and D21S11 in 197 unrelated Danes. We used a new STR nomenclature that depicts the locus name used in forensic genetics, the length of the repeat region divided by the repeat length (typically 4 nucleotides) and detailed sequence information of possible sub-repeats and SNPs within the amplified fragment.
Analysis of artificially degraded DNA using STRs and SNPs—results of a collaborative European (EDNAP) exercise
2005
Recently, there has been much debate about what kinds of genetic markers should be implemented as new core loci that constitute national DNA databases. The choices lie between conventional STRs, ranging in size from 100 to 450 bp; mini-STRs, with amplicon sizes less than 200 bp; and single nucleotide polymorphisms (SNPs). There is general agreement by the European DNA Profiling Group (EDNAP) and the European Network of Forensic Science Institutes (ENFSI) that the reason to implement new markers is to increase the chance of amplifying highly degraded DNA rather than to increase the discriminating power of the current techniques. A collaborative study between nine European and US laboratories…
DNA Commission of the International Society of Forensic Genetics: recommendations on forensic analysis using Y-chromosome short tandem repeats
2001
Abstract During the past few years the DNA commission of the International Society of Forensic Genetics has published a series of documents providing guidelines and recommendations concerning the application of DNA polymorphisms to the problems of human identification. This latest report addresses a relatively new area, namely Y-chromosome polymorphisms, with particular emphasis on short tandem repeats (STRs). This report addresses nomenclature, use of allelic ladders, population genetics and reporting methods.