基于光微流激光阵列的快速准确DNA分析与筛查

项目名称： 基于光微流激光阵列的快速准确DNA分析与筛查

项目编号： No.61471254

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 范旭东

作者单位： 太原理工大学

项目金额： 81万元

中文摘要： 实现完全配对与单碱基错配DNA检测对疾病诊断和生化基础研究具有非常重要的意义。高分辨熔解曲线分析(HRM)是近年来兴起的一种简便、可实现DNA突变快速扫描的后聚合酶链反应技术。然而随着序列长度的增加，不同DNA所产生荧光强度差异越来越小，将难以分辨。 本项目提出一种基于光微流激光的腔内高灵敏度HRM检测方法，可用来分辨具有上千碱基对的DNA序列，所需样品低至纳升量级。DNA样品及荧光素被用做激光器增益介质，与传统HRM相比：1) 激光取代荧光被用做传感信号，利用共振腔极强光反馈，有望将传统HRM中的传感信号差提高数千至数万倍；2)利用激光器由受激辐射到自发辐射锐利相变过程，可精确标定不同DNA熔解温度；3)提供了一种保持温度恒定，检测信号强度随激发光强变化这一快速、高通量的新型检测方法；4)与PCR及微流控技术高度兼容，可实现芯片上检测。本项目的实现可推动生物医药应用和相关研究领域的发展。

中文关键词： 光学生化传感器；高通量检测；PCR检测；突变检测

英文摘要： Distinguishing the target DNA from the single-base mismatched counterpart provides critical information for disease diagnosis and basic biochemical research. High resolution melting (HRM) is a newly developed post-PCR (polymerase chain reaction) analysis method for identifying genetic variation. It employs fluorescence from intercalating dyes to differentiate the melting curve of two DNA sequences. As compared to other DNA analysis methods, HRM is simple and fast. However, with the increase of DNA length, the resulting fluorescence difference between the target and the single-base mismatched DNA becomes very small, which can not be easily distinguished. How to sensitively discern the small intrinsic thermal dynamic difference becomes crucial when we analyze two DNA sequences of thousands of bases long but that differ by only a single base. We propose to develop a paradigm-changing intra-cavity DNA melting analysis with an optofluidic DNA laser that is capable of differentiating single-base mismatched DNAs of thousands of bases long in nano-liter sized solution. In this scheme, DNA samples, probes, and fluorophores are flowed inside a laser cavity, thus becoming part of the DNA laser gain medium. As compared to conventional HRM, the proposed intra-cavity analysis has many distinct advantages. (1) It employs stimulated laser emission, rather than fluorescence as the sensing signal. Due to the strong optical feedback provided by the laser cavity, the small signal difference between the target and the single-base mismatched DNA will be significantly amplified for a few orders of magnitudes even with DNA of thousands of bases long. (2) When temperature increases, the laser undergoes a sharp phase transition from stimulated emission and spontaneous emission, which allows us to precisely determine the melting temperature difference of two DNA sequences; (3) In addition to temperature ramping, the high differential signal allows us to scan the excitation with different pumping intensities at a fixed temperature to distinguish two DNA sequences, which provides another means for rapid, high-throughput DNA analysis; (4) The optofluidic DNA laser is highly compatible with on-chip PCR and requires only nano-liter sized sample volumes. The realization of this project can promote the application in biomedic and other related fields.

英文关键词： Optical Biochemical Sensing;High Throughput Detection;PCR Detection;Mutation Detection