Generating DNA profiles from immunochromatographic cards using LCN methodology

The aim of this research was to obtain DNA profiles from immunochromatographic test devices which have already yielded positive results with body fluids obtained from fourteen volunteers. Three different immunochromatographic cards for the identification of human blood and one for the identification of human saliva were used for this research. Each body fluid was detected using the appropriate immunochromatographic card. The used cards were kept at room temperature for various lengths of time. The membranes were removed at the end of the designated times and the entire strip was extracted using low copy number (LCN) extraction procedure. The extracted DNA was amplified using reduced amplification volume and higher PCR cycle numbers. Autosomal STR profiles were detected using AmpFℓSTR^® Identifiler™ PCR Amplification Kit from Applied Biosystems (AB). Additionally, DNA extracted from the male volunteers was amplified using the AB AmpFℓSTR^® Yfiler™ PCR Amplification Kit. Analysis of the amplified products was carried out by capillary electrophoresis injection on the AB 3130xl Genetic Analyzer. The generated DNA data was analyzed using the SoftGenetics GeneMarker^® HID Version 1.7 software.Autosomal and Y-STR DNA profiles were obtained from most of the cards which were stored at room temperature for up to three months. DNA profile was obtained from all four types of the immunochromatographic cards used in this study. These profiles were concordant with the profiles obtained from the donors’ reference samples.     

Comparative Analysis of the Effects of Heat on the PCR‐Amplification of Various Sized DNA Fragments Extracted from Sus Scrofa Molars*

Abstract: This study examined the effects of heat on the amplification of DNA from the dental pulp of Sus scrofa molars and investigated the protection afforded to the pulp tissue by the dental enamel, alveolar process, and soft tissue of the head. Segments of defleshed maxilla and mandible encasing the first molar (n = 60) were subject to a range of temperatures for 15 min. Dental pulps were retrieved. Amplifications using three‐primer and four‐primer multiplexes showed no degradation of the largest fragment following exposure to 450°C. Amplifications in the three‐primer multiplex (283 bp) were successful following exposure to 525°C in maxillary samples only. This study revealed the enamel density of maxillary molars to be greater than mandibular molars in Sus scrofa. Following incineration of intact heads for 15 min (n = 10) and 1 h (n = 4) at an average temperature of 625°C, amplifications of the largest fragment (450 bp) were successful from both maxillary and mandibular teeth.     

Recovery of Environmental Human DNA by Insects*,†

Abstract: We tested the hypotheses that foraging insects can acquire human DNA from the environment and that insect‐delivered human DNA is of sufficient quantity and quality to permit standard forensic analyses. Houseflies, German cockroaches, and camel crickets were exposed to dusty surfaces and then assayed for human mitochondrial and nuclear loci by conventional and qPCR, and multiplex STR amplification. Over two experiments, 100% of insect groups and 94% of dust controls tested positive for human DNA. Of 177 individuals, 33–67% tested positive and 13 yielded quantifiable human DNA (mean = 0.022 ± 0.006 ng; mean dust control = 2.448 ± 0.960 ng); four had at least one positive allele call for one or more locus; eight others showed multiple peaks at some loci. Results imply that application to routine forensic casework is limited given current detection methodology yet demonstrate the potential use of insects as environmental samplers for human DNA.     

犯罪心理测试反测试及其对策

犯罪心理测试技术是在甄别嫌疑人过程中使用的测谎方法.但由于测试中的原理机制等问题,反测试手段可以以多种方式对测过程和测试结果进行干扰.加强犯罪心理测试中的监控并提高反测试识别技术,可以较好地应对测试中出现的反测试.反测试的出现本身就是逃避测试的表现,一旦发现被测人存在反测试行为或心理,则应重点对其进行调查.随着新技术的发展,脑电测试结合测谎范式进行检测有了一定的研究基础,为今后的测谎方式提供了更多的选择.     

Ultrafast Amplification of DNA on Plastic Microdevices for Forensic Short Tandem Repeat Analysis

The majority of microfluidic devices used as a platform for low‐cost, rapid DNA analysis are glass devices; however, microchip fabrication in glass is costly and laborious, enhancing the interest in polymeric substrates, such as poly (methyl methacrylate) (PMMA), as an inexpensive alternative. Here, we report amplification in PMMA polymerase chain reaction (PCR) microchips providing full short tandem repeat profiles (16 of 16 loci) in 30–40 min, with peak height ratios and stutter percentages that meet literature threshold requirements. In addition, partial profiles (15 of 16 loci) were generated using an ultrafast PCR method in 17.1 min, representing a ~10‐fold reduction in reaction time as compared to current amplification methods. Finally, a multichamber device was demonstrated to simultaneously amplify one positive, one negative, and five individual samples in 39 min. Although there were instances of loci dropout, this device represents a first step toward a microfluidic system capable of amplifying more than one sample simultaneously.     

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.     

从运动生化视角谈基层民警力量训练

基层民警力量训练存在着训练意识不强、训练方法不科学、重技能轻体能、健身器械和场馆不足等问题,应该从运动生物化学的角度出发,运用运动生物化学反应基本原理指导警察力量训练,遵循运用生物化学基本原理进行力量训练原则,依据运动生物化学原理进行力量训练,以提高基层民警力量训练的实效。     

Simple and Sensitive Method for Identification of Human DNA by Allele-Specific Polymerase Chain Reaction of FOXP2

Abstract:  The forkhead box P2 ( FOXP2 ) gene is specifically involved in speech and language development in humans. The sequence is well conserved among many vertebrate species but has accumulated amino acid changes in the human lineage. The aim of this study was to develop a simple method to discriminate between human and nonhuman vertebrate DNA in forensic specimens by amplification of a human-specific genomic region. In the present study, we designed an allele-specific polymerase chain reaction (PCR) using primers to amplify smaller than 70-bp regions of FOXP2 to identify DNA as being of human or nonhuman, including ape, origin. PCR amplification was also successfully performed using fluorescence-labeled primers, and this method allows a single PCR reaction with a genomic DNA sample as small as 0.01 ng. This system also identified the presence of human DNA in two blood stains stored for 20 and 38 years. The results suggested the potential usefulness of FOXP2 as an identifier of human DNA in forensic samples.     

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.     

实时RT-PCR检测大鼠死后管家基因mRNA的时序性降解

目的研究实时荧光定量RT—PCR方法检测死亡大鼠管家基因mRNA时序性降解的可行性,为死亡时间（Dostmortem interval,PMI）推断寻找新的研究手段。方法应用SYBR Green Ⅰ实时荧光定量RT—PCR技术．检测死后不同时间大鼠脑和脾中管家基因GAPDHmRNA及β—actinmRNA的水平,结果用循环阈值（简称Ct值）表示,分析死后经过时间与Ct值的线性关系,并建立死亡时间推断回归方程。结果GAPDH mRNA和β—actinmRNA的Ct值均与PMI之间存在显著的相关性。结论SYBR GreenⅠ实时荧光定量RT—PCR在定量分析mRNA降解的研究中是一个较理想的技术手段。选用管家基因作为PMI推断的研究对象,可在法医检案中消除其他基因因为个体差异带来的误差,更具实用性。Ct值作为动态监测机体死后不同时间点的客观指标．与死后不同时间点的线性关系良好,推断死后经过时间尤其是晚期死亡时间较为理想。