Exciplex detection: application of (i) novel detector systems and (ii) software for signal extraction from noise

Exciplex 检测：应用 (i) 新型检测器系统和 (ii) 从噪声中提取信号的软件

• 批准号: BB/E000223/1
• 负责人: Kenneth Thomas Douglas
• 金额: $ 11.01万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FE000223%2F1
• 关键词: Exciplex; detection; application; novel; detector

One of the major scientific advances of recent years has been the inreasing use of information based on DNA samples to help in decision-making in many aspects of everyday life. Immediately obvious examples are the forensic uses of DNA, or medical uses, such as methods for diagnosing disease or potential pathogens. The determination of DNA sequence of the human genome recently has been followed by many similar genome deteminations that should serve to improve or health and safety. A huge number of methods to detect particular regions of a DNA sample, such as from a patient or a potential disease-causing organism, depend on our ability to detect light emission called fluorescence. Naturally, the aim is use as little material as possible in any detemination and for this reason we are seeking ways to minimise any background fluorescence that the DNA analysis method possesses. At Manchester University a new method has recently been developed in which two molecules that do not have any intrinsic fluorescence are brought together on the particular sequence of DNA that is to be detected. The detection molecules have to be very precisely arranged in space for successful fluorescence emission. This correct arrangement of the detector molecules is actually enforced by the DNA target sequence itself. The background fluorescence in this system is less than 1% (this can be compared with other current fluorescence probes for DNA that typically have backgrounds of greater than 60%). By careful design of the chemical structures of these two probe molecules, the system is only able to emit strong fluorescence when exactly the correct DNA sequence has been found. If even a single DNA base is incorrect in the sample sequence, the fluorescence emission is not detectable. This new project extends the scope of these target-assembled exciplex detection of DNA sequences using input of Leicester Space Centre scientists and Edinburgh University astrophysicists. Since 2001 the University of Leicester Space Research Centre (SRC) and Department of Biology, together with the Space Science Department at ESA/ESTEC, have been investigating the application of detectors developed for space astronomy to optical fluorescence measurements in the life sciences and medicine. Their work with superconducting tunnel junctions (STJs) has led to an STJ-based 'scanner' to replace the current types of detectors (CCD- and photomultiplier tube (PMT)-based) for the readout of microarrays or gene chips, for cellular imaging, protein arrays, flow cytometry and many other applications. The STJ offers sensitivity advantages of at least 100 times compared to a silicon CCD and conventional photomultiplier tubes (PMTs) while uniquely measuring the spectral form of fluorescence intensity on a photon-by-photon basis. This new system wil be applied to the DNA exciplexes and allow not only more sensitive measurment, but also a detection system that provides different information from instruments previously used in this context. The above detection methods have concerned themselves with the intensity of the colour of the fluorescence light. However, fluorescence has an additional property - it takes place over a very short (nanosecond), but discrete and measurable, time period. The pattern of the time dependence for these DNA exciplexes is rather complex and this very complexity allows its potential use as a unique badge of the presence or otherwise of such an exciplex in an unknown sample. The detemination of unique patterns of timed events is a common problem in cosmology and so the astronomy groups at Edinburgh University are going to apply their specialist mathematical methods to developing new ways to detect the exciplex time signarure. It is likely that detection using this novel approach will allow the system to be used for very low concentratins - possibly lower than could ever be used based on fluorescence colour insensity alone.

近年来的主要科学进步之一是使用基于DNA样本的信息陷入困境，以帮助日常生活许多方面的决策。明显的例子是DNA或医疗用途的法医用途，例如用于诊断疾病或潜在病原体的方法。最近，人类基因组的DNA序列的测定之后是许多类似的基因组因式，应改善健康和安全。检测DNA样品的特定区域的大量方法，例如患者或潜在的引起疾病的生物，取决于我们检测到被称为荧光的光发射的能力。自然，其目的是在任何局限性中使用尽可能少的材料，因此，我们正在寻求方法来最大程度地减少DNA分析方法所拥有的任何背景荧光。在曼彻斯特大学，最近开发了一种新方法，其中两个没有任何固有荧光的分子在要检测到的特定DNA序列上聚集在一起。检测分子必须非常精确地排列在成功的荧光发射中。检测器分子的正确排列实际上是由DNA靶序序本身实现的。该系统中的背景荧光小于1％（可以将其与通常具有大于60％的背景的DNA的其他当前荧光探针进行比较）。通过仔细设计这两个探针分子的化学结构，只有在发现正确的DNA序列时才能发出强荧光。如果在样品序列中，即使单个DNA碱基也不正确，则无法检测到荧光发射。这个新项目扩展了这些目标组装的分组序列检测DNA序列的范围，使用莱斯特太空中心科学家和爱丁堡大学天体物理学家的输入。自2001年以来，莱斯特大学太空研究中心（SRC）和生物学系与ESA/ESTEC的太空科学系一起，一直在研究为太空天文学而在生命科学和医学中开发的探测器在光学荧光测量中开发的探测器。他们使用超导隧道连接（STJ）的工作导致了基于STJ的“扫描仪”，以取代当前类型的探测器（基于CCD和PhotoMultipliper tube（PMT） - 基于PMT），以读取微阵列或基因芯片，用于用于细胞成像，蛋白质阵列，流式细胞仪和许多其他应用程序。与硅CCD和常规的光电倍增管（PMTS）相比，STJ具有至少100倍的敏感性优势，同时以逐个光子为基础测量荧光强度的光谱形式。该新系统将应用于DNA动力学上，不仅允许更敏感的测量，还允许检测系统提供与以前在这种情况下使用的工具不同的信息。上述检测方法与荧​​光颜色的强度有关。但是，荧光具有额外的特性 - 它发生在非常短的（纳秒）中，但离散且可测量的时间段。这些DNA依赖性的时间依赖模式相当复杂，这种复杂性允许其作为在未知样品中这种偏心的独特存在或其他方式的独特徽章的潜在用途。定时事件的独特模式的谴责是宇宙学中的一个常见问题，因此，爱丁堡大学的天文学组将应用其专业数学方法来开发新方法来检测Expiplex时间符号。使用这种新型方法的检测可能会使系统用于非常低的浓缩素 - 可能仅基于荧光颜色iNSensity而低。