Search results for "STR analysis"
showing 7 items of 7 documents
Comparative analysis of short tandem repeats and single nucleotide polymorphisms on the Y-chromosome in Germans, Chinese and Thais.
2003
We have typed genomic DNA samples from 95 individuals from Western Germany, 78 individuals from Bangkok/Thailand and 56 individuals from Chengdu/China for 11 Y-chromosomal diallelic polymorphisms and eight short tandem repeat (STR) systems. For single nucleotide polymorphism (SNP) analysis, a rapid method was applied using the single base extension technology (minisequencing) in combination with capillary electrophoresis. PCR products for SRY-8299, Tat, SRY2627, 92R7, SRY1532, M9, M13, M17/M19 and M20 were pooled and used as templates for the commercially available SNaPshot kit. In addition to these ten SNPs we also tested the Y-chromosomal diallelic Alu repeat insertion DYS287 (YAP) by aga…
STR analysis of artificially degraded DNA--results of a collaborative European exercise.
2003
Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak heig…
Development of a new multiplex assay for STR typing of telogen hair roots
2006
Abstract We have developed a new strategy in which 10 STR systems plus amelogenin were simultaneously amplified from telogen hair roots with maximal fragment sizes smaller than 270 base pairs. The multiplex 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 and short amplicon sizes (D2S1338, D12S391, TPOX and D5S818). Due to the biotinylation of the reverse primers from five STRs systems, these PCR products can be separated from the other six amplicons after PCR amplification. The two sub-multiplexes were then analyzed in two different runs on …
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…
Tandem repeat structure of the duplicated Y-chromosomal STR locus DYS385 and frequency studies in the German and three Asian populations
1998
The Y-chromosomal short tandem repeat (STR) locus DYS385 can be typed using PCR amplification and separation of the resulting polymorphic fragments by non-denaturing high resolution polyacrylamide gel electrophoresis followed by silver staining. The PCR primers amplify a duplicated repeat sequence on the Y chromosome revealing a two-band pattern in male individuals. To determine the internal repeat structure as a basis for a consensus nomenclature, DNA sequence analysis was carried out after subcloning of PCR-amplified fragments revealing the uniform 4-bp repeat structure 'GAAA'. The shortest allele observed consisted of 10 repeat units thus providing the basis for the designation 'allele 1…
The effect of whole genome amplification on samples originating from more than one donor
2006
Abstract In this study, the GenomiPhi™ DNA Amplification Kit (Amersham Biosciences) was used to investigate the potential of whole genome amplification (WGA) when considering samples originating from more than one donor. DNA was extracted from blood samples, quantified and normalised before being mixed in ratios of 1:1, 1:3, 1:7 and 1:15. Proportions were checked using standard STR analysis before being subjected to WGA. Once amplified using GenomiPhi™, the ratios were again checked. Relative proportions were found to be maintained in the 1:1 and 1:3 ratios following WGA; the observed peak ratios were found to match the expected peak ratios regardless of the starting concentration of DNA. W…