荧光原位杂交技术在一些临床重要疾病的诊断或治疗中具有重要地位，甚至是“金标准”。目前该方法存在试剂制备成本高、检测实验条件严苛、耗时较长等缺点，CRISPR/dCas9荧光原位标记检测技术可以弥补这些不足，但其信号往往较弱。研究提示将编码包含MS2-motif的sgRNA质粒与编码dCas9和MCP-荧光蛋白的质粒共同转入活细胞，可实现活细胞荧光动态标记的信号放大；我们前期研究也证实，MS2-motif可与MCP特异性识别并结合。因此，本课题拟利用MS2-motif构建可用于临床诊疗的固定细胞CRISPR/dCas9荧光原位标记信号放大检测方法，并验证其信号放大效果；同时，将新建方法应用于染色体非整倍体DNA、HER2 DNA、HER2 mRNA和EB病毒RNA检测，从DNA标记和RNA标记两个方面评估其在临床分子诊断中的应用价值，以期为相关疾病的临床分子诊断提供新的思路和方法。

Fluorescence in situ hybridization plays an important role in the diagnosis and treatment of many important diseases, even as the "gold standard". However, the high cost, harsh treatment and time-consuming process have limited its application. CRISPR/dCas9 mediated in situ labeling method could overcome these obstacles, but its signal is traditionally weak. It has been reported that the signal amplification of dynamic labeling could be achieved by transferring sgRNA plasmid vector harboring MS2-motifs into living cells together with the plasmid vector encoding dCas9 and MCP-fluorescence fusion protein. Our previous studies also confirmed that MS2-motif could specifically identify and bind to MCP. Therefore, we intend to establish CRISPR/dCas9-mediated in situ labeling methods using MS2-motif for signal amplification purpose, which could be used in the clinical diagnosis and treatment, and subsequently verify its signal amplification capacity. Meanwhile, we apply this newly established method to the detection of chromosome aneuploidy DNA, HER2 DNA, HER2 mRNA and EB virus RNA, and evaluate its performance in clinical molecular diagnosis from two aspects of DNA labeling and RNA labeling to provide new ideas and methods for clinical molecular diagnosis of related diseases.