High‐Throughput STR Analysis for DNA Database Using Direct PCR,

Since the Korean criminal DNA database was launched in 2010, we have focused on establishing an automated DNA database profiling system that analyzes short tandem repeat loci in a high‐throughput and cost‐effective manner. We established a DNA database profiling system without DNA purification using a direct PCR buffer system. The quality of direct PCR procedures was compared with that of conventional PCR system under their respective optimized conditions. The results revealed not only perfect concordance but also an excellent PCR success rate, good electropherogram quality, and an optimal intra/inter‐loci peak height ratio. In particular, the proportion of DNA extraction required due to direct PCR failure could be minimized to <3%. In conclusion, the newly developed direct PCR system can be adopted for automated DNA database profiling systems to replace or supplement conventional PCR system in a time‐ and cost‐saving manner.     

A Molecular Key for the Identification of Blow Flies in Southeastern Nebraska*

Abstract: Immature blow flies (Calliphoridae) are typically the first colonizers of cadavers. Identification of the early instars using traditional, morphology‐based keys is difficult because of their small size, similarity, and simplicity in external morphology. Information derived from molecular genetic data would augment the accurate identification of immature flies. Nine species of blow flies commonly found in southeastern Nebraska were used to examine the utility of molecular‐based keys. Polymerase chain reaction–restriction fragment length polymorphisms (PCR–RFLP) were investigated with 10 common, inexpensive, restriction enzymes from an amplicon of approximately 1500 bp spanning the mitochondrial cytochrome oxidase I gene. A simple molecular taxonomic key, comprising RFLP from the restriction enzymes HinfI and DraI, enabled the differentiation of all species used. Further development of PCR–RFLP, including more extensive and intensive examination of blow flies, would benefit forensic laboratories in the accurate identification of evidence consisting of immature blow flies.     

脱落毛发线粒体DNA HV1区序列测定的研究

目的　对脱落毛发线粒体DNAHV1区序列测定方法进行研究。方法　嵌合扩增结合末端荧光标记DNA测序。结果　对 2 0例脱落毛发进行分析获得了明确的测序结果 ,与来自同一个体的血液所测得的DNA序列进行比较 ,完全相同。结论　嵌合扩增在对脱落毛发进行线粒体DNA多变区序列分析中是一种有效的方法 ,在法医DNA检验中具有实用价值。     

Measuring the impact of forensic science in detecting burglary and autocrime offences

As UK investment in forensic science has increased, the government has taken a fresh interest in how far this has led to dividends in terms of the detection of crime and its reduction. The Home Office funded 'Pathfinder Project' sought to monitor and document the complex relationships between the collection and use of forensic material (looking at a range of forensic science techniques) and its impact on crime detection. The project specifically targeted the 'volume' crimes of burglary and vehicle crime. Detailed data was gathered on all stages of the process between the collection and use of forensic material and crime detection. The model falls into two conceptual phases--scene attendance to suspect identification and identification to detection. From the analysis it was found that approximately one third of burglary and autocrime scenes are visited by SOCOs. While scientific identifications are only made in a minority of burglary and autocrime offences overall, it belies their importance. About one in ten of burglary and autocrime cases are cleared up by the police and it is estimated that fingerprints and SGMPlus were a contributory factor in achieving one third of these clear ups.     

The likelihood approach to compare populations: a study on DNA evidence and pitfalls of intuitions

The paper follows on from earlier work [Taroni F and Aitken CGG. Probabilistic reasoning in the law, Part 1: assessment of probabilities and explanation of the value of DNA evidence. Science & Justice 1998; 38: 165-177]. Different explanations of the value of DNA evidence were presented to students from two schools of forensic science and to members of fifteen laboratories all around the world. The responses were divided into two groups; those which came from a school or laboratory identified as Bayesian and those which came from a school or laboratory identified as non-Bayesian. The paper analyses these responses using a likelihood approach. This approach is more consistent with a Bayesian analysis than one based on a frequentist approach, as was reported by Taroni F and Aitken CGG. [Probabilistic reasoning in the law, Part 1: assessment of probabilities and explanation of the value of DNA evidence] in Science & Justice 1998.     

Comparative Analysis of the HV1 and HV2 Regions of Human Mitochondrial DNA by Denaturing High-Performance Liquid Chromatography

Abstract:  Denaturing high-performance liquid chromatography (DHPLC) was evaluated as a sequencing-independent means of detecting the presence of sequence differences in pair-wise mixtures of nonconcordant amplicons of human mitochondrial DNA (mtDNA). A total of 920 pair-wise combinations of HV1 and HV2 mtDNA amplicons from 95 individuals were assayed by DHPLC for sequence concordance/nonconcordance. For the 72 combinations of amplicons from different individuals who shared identical DNA sequences, DHPLC assays consistently indicated sequence concordance between the samples. This was in 100% agreement with sequencing data. For the 849 combinations of amplicons which differed in sequence, DHPLC detected the presence of sequence nonconcordance in all but 13 assays to yield 98.5% concordance with sequencing. Thus, DHPLC can be used to detect a diversity of sequence differences (transitions, transversions, insertions, and deletions) in the mtDNA D-loop. Accordingly, DHPLC may have utility as a presumptive indicator of mtDNA sequence concordance samples, as a screen for heteroplasmy/situational mixtures, and as a means for the physical fractionation of the individual contributors to an mtDNA mixture prior to sequencing.     

Concordance Between the AmpFℓSTR® MiniFiler™ and AmpFℓSTR® Identifiler® PCR Amplification Kits in the Kuwaiti Population

Abstract:  The AmpFℓSTR^® MiniFiler™ polymerase chain reaction amplification kit, developed and supplied by Applied Biosystems, complements the AmpFℓSTR^® Identifiler^® polymerase chain reaction amplification kit (Applied Biosystems, Warrington, U.K.) by improving the success rate when profiling DNA that is degraded or contains inhibitors. Before applying the MiniFiler™ kit to casework, the profiles from 200 unrelated Kuwaitis were compared to Identifiler^® profiles. Concordance was observed for 99.875% (1598 of 1600) of the compared STR loci. The two discordant profiles displayed allelic dropout: one at the D13S317 locus due to nonamplification of allele 10 in the MiniFiler™ profile, and one at the D18S51 locus due to nonamplification of allele 18 in the Identifiler^® profile.     

Degeneration of Nuclei and Mitochondria in Human Hairs

Abstract:  It is generally accepted that nuclei degrade in developing hair shafts but the point at which such occurs has not been investigated. The fate of mitochondria in the keratinizing hair shaft has been less clear. This study uses transmission electron microscopy to investigate when nuclei and mitochondria are no longer visible in the developing hair shaft. Serial sections were obtained from anagen head hairs absent follicles in order to determine the sequence of degradation of nuclei and mitochondria in the hair shaft by starting at the root bulb and proceeding toward the hair tip. It was demonstrated that nuclei and mitochondria become invisible in the keratinizing hair shaft at about the same time. This was found to occur fairly early in the process at the level of the hair shaft where the hair cuticle becomes permanent.     

Application of DNA Forensic Techniques for Identifying Poached Guanacos (Lama guanicoe) in Chilean Patagonia*

Abstract: Guanaco (Lama guanicoe) is a protected and widely distributed ungulate in South America. A poacher, after killing guanacos in Valle Chacabuco, Chilean Patagonia, transported and stored the meat. Samples were retrieved by local police but the suspect argued that the meat was from a horse. Mitochondrial cytochrome b gene (774 pb), 15 loci microsatellites, and SRY gene were used to identify the species, number of animals and their population origin, and the sex of the animals, respectively. Analysis revealed that the samples came from a female (absence of SRY gene) Patagonian guanaco (assignment probability between 0.0075 and 0.0282), and clearly distinguishing it from sympatric ungulates (E‐value = 0). Based on the evidence obtained in the field in addition to forensic data, the suspect was convicted of poaching and illegally carrying fire arms. This is the first report of molecular tools being used in forensic investigations of Chilean wildlife indicating its promising future application in guanaco management and conservation.     

Validation of the AMPFℓSTR® MiniFilerTM PCR Amplification Kit for Use in Forensic Casework*

Abstract: The AmpF?STR^® MiniFiler^TM PCR Amplification Kit is designed to genotype degraded and/or inhibited DNA samples when the AmpF?STR^® Identifiler^TM PCR Amplification Kit is incapable of generating a complete genetic profile. Validation experiments, following the SWGDAM guidelines, were designed to evaluate the performance of MiniFiler. Data obtained demonstrated that MiniFiler, when used in conjunction with Identifiler, provided an increased ability to obtain genetic profiles from challenged samples. The optimum template range was found to be between 0.2 and 0.6 ng, with 0.3 ng yielding the best results. Full concordance was achieved between the MiniFiler kit and Identifiler kit except in a single case of a null allele at locus D21S11. Numerous instances of severe heterozygous peak imbalance (<50%) were observed in single source samples amplified within the optimum range of input DNA suggesting that caution be taken when attempting to deduce component genotypes in a mixture.