中文摘要：

DNA测序技术是遗传基因组相关疾病研究的基础。合成测序是DNA二代测序技术中非常重要的一种。合成测序技术能够有效地实现大规模平行测序,大大提高测序通量的同时也降低成本,目前已得到广泛的应用。在合成测序中,首先需要合成荧光素标记的核苷酸,作为能够参与DNA链延伸的循环可逆终端。已有文献报道的可逆终端结构主要包括单位点修饰（MRT）和双位点修饰（DRT）两种类型。DRT类型可逆终端的最大优势是DNA聚合酶容易识别且合成路线简单,能够较好地应用于DNA合成测序。在此过程中可断裂连接单元将核苷酸和荧光素连接起来,它的性质直接决定了测序的效率、读长等关键指标。本文主要对目前用于DNA合成测序的可断裂连接单元研究现状进行介绍,并对其发展前景进行了展望。

英文摘要：

DNA sequencing technology is the basis of genetical genomics-related diseases.Sequencing by synthesis is one of the most important second-generation DNA sequencing techniques.Sequencing by synthesis can achieve a massively parallel sequencing effectively and improve sequencing throughput greatly,which favor cost reduction.Therefore,sequencing by synthesis has been widely used over the world.In DNA sequencing by synthesis,fluorescence-labeled nucleotides should be synthesized as a cyclic reversible terminator for DNA extension reaction.The reversible terminators reported in the literature mainly include MRT（mono-modified reversible terminators） and DRT（dual-modified reversible terminators） reversible terminators.The most significant advantage of DRT reversible terminator is that it can be readily identified by DNA polymerase.Besides,the synthetic route of MRT is simple,and this type of reversible terminator is hence more suitable for DNA sequencing by synthesis.Since fluorescence-labeled nucleotides are usually prepared by connecting the fluorescence tag and the nucleotide with a cleavable linker,the properties of the cleavable linker exert significant effects on the key parameters of DNA sequencing such as sequencing efficiency and read length.In this paper,recent advances and current research status of cleavable linkers used in DNA sequencing by synthesis is reviewed.Also,the development prospect of the cleavable linkers is demonstrated.