At scene of crime DNA characterisation

法医科学是打击犯罪的重要工具，这项提案将建立在前沿研究的基础上，创造一种技术，这种技术将彻底改变DNA指纹识别在犯罪现场的使用方式，从而在迫切需要的地方产生快速准确的答案。在过去的十年中，DNA指纹识别与国家数据库的建立一起，以其独特的分析能力对嫌疑人进行生物特征分析，已成为打击犯罪的最重要的法医工具之一。目前，这种分析是在实验室环境中进行的，需要从犯罪现场收集样本，然后运送到中央设施进行后续分析。目前的实践显然增加了额外的运输和存储时间，这反过来又增加了成本，并增加了不必要的分析时间延迟。因此，以实地为基础的方法的发展在产生更快速的基于dna的情报方面可能是最有价值的。这种能力不仅可以在不到30分钟的时间内获得DNA图谱，而且这种方法的并行操作将允许在犯罪现场被污染或损坏之前运行相当大量的样本。虽然进行DNA分析所需的基本分析方法已经建立良好（即从生物样品中提取和纯化DNA，通过聚合酶链反应（PCR）扩增目标DNA，电泳大小分离和DNA片段的荧光检测），但开发一种集成这些迄今为止独立功能的便携式设备是一个独特的挑战，这构成了本提案的基础。为了实现真正的手持便携性，该技术需要在机械和化学/生物化学方面具有稳健性，并且对基于电池的操作具有低功耗要求。在这个拟议的项目中，申请人的综合专业知识将集中在生成一个原型仪器上，该仪器将满足上述可移植性要求。这项工作建立在早期令人鼓舞的研究基础上，其中微流体方法加上高效的微波加热已被证明适用于DNA样品的PCR扩增。微流体方法提供了小样本能力（微升），已经被包括申请人在内的许多研究人员证明，提供了一种快速的热PCR循环过程方法，表明实际处理时间约为20分钟。在扩增目标DNA后，可以使用基于毛细管电泳的分离与荧光检测有效地进行分析，微流体方法再次证明了其优势，可以在几分钟内提供高效快速的分离过程。在此应用程序中开发的原型将基于集成的微流体歧管或芯片，该芯片将实现样品提取/预浓缩，PCR扩增和DNA片段分离，同时通过使用手动和电动流体泵送，低功率固态微波加热和低功率荧光检测来开发低功耗要求。虽然所指出的所有样品处理阶段都已分别进行了演示，但必须强调的是，将它们整合在一个集成单元中，并在每个阶段具有兼容的功能和要求，这是一个真正的科学挑战。如果成功，该产品将成为一种新颖的低成本但功能强大的技术，将在打击犯罪方面立即受益。我们知道这并不容易，但我们相信围绕该提案组建的研究团队可以完成这项工作，并打破目前存在的成功集成障碍。

Forensic science is an important tool in the fight against crime and this proposal will build on cutting edge research to create technology that will revolutionise the way DNA fingerprinting can be used at crime scenes to generate quick and accurate answers where they are urgently needed. Over the past decade DNA fingerprinting, together with the establishment of a national database, has becoming one of the most important forensic tools in the fight against crime, with its unique analytical capability to biometrically profile suspects. At present such analysis is carried out in the laboratory environment which requires samples to be collected from the scene of a crime, and then be transported to a central facility for subsequent analysis. This current practice clearly adds additional transport and storage time which in turn increase costs and adds unwanted delays in analysis times. Therefore the development of field-based methodology could prove to be most valuable in generating more rapid DNA-based intelligence. Such capability will not only allow DNA profiles to be obtained in say less than 30 minutes but the parallel operation of such methodology will allow reasonably large numbers of samples to be run before the crime scene becomes contaminated or corrupted. Whilst the basic analytical methodology required to carry out DNA analysis is well established (i.e. extraction and purification of the DNA from the biological sample, amplification of the target DNA by polymerase chain reaction (PCR) and electrophoretic size separation and fluorescent detection of the DNA fragments) the development of a portable device which integrates these hitherto separate functions is a unique challenge which form the basis of this proposal.In order to achieve true hand-held portability the technology needs to be mechanically and chemically/biochemically robust and have low power requirements for battery-based operation. In this proposed project the combined expertise of the applicants will be focused on generating a prototype instrument that will meet the portability requirements outlined above. The work builds on early encouraging research in which micro fluidic methodology coupled with efficient microwave-based heating has been demonstrated to be suitable for the PCR amplification of DNA samples. The micro fluidic approach, which offers small sample capability (microlitres), has already been shown by number of researchers, including the applicants, to offer a rapid approach to the thermal PCR cyclic process suggesting realistic processing times of around 20 minutes. Following amplification of the target DNA, analysis can effectively be performed using capillary electrophoresis-based separations with fluorescence detection and once again the micro fluidic approach has proved advantageous in offering an efficient and rapid separation process within a few minutes. The prototype developed in this application will be based on an integrated micro fluidics manifold or chip that will enable sample extraction/preconcentration, PCR amplification and DNA fragment separation to be achieved whilst exploiting low power requirements by using manual and electrokinetic fluidic pumping, low power solid state microwave-based heating and low power fluorescent detection. Whilst all of the sample processing stages indicated have been demonstrated separately, it is important to stress that there is a real scientific challenge in bringing them all together in an integrated unit with compatible functions and requirements at each stage. If successful, the product will be an example of novel low-cost but highly functional technology, which will be of immediate benefit in the fight against crime. We know this is not going to be easy but we believe the research team assembled around this proposal can get the job done and break the integration barrier to success that currently exists.