Guanine (G)-rich sequences in nucleic acids can assemble into G-quadruplex structures that involve G-quartets linked by loop nucleotides. The structural and topological diversity of G-quadruplexes have attracted great attention for decades. Recent methodological advances have advanced the identification and characterization of G-quadruplexes in vivo as well as in vitro, and at a much higher resolution and throughput, which has greatly expanded our current understanding of G-quadruplex structure and function. Accumulating knowledge about the structural properties of G-quadruplexes has helped to design and develop a repertoire of molecular and chemical tools for biological applications. This review highlights how these exciting methods and findings have opened new doors to investigate the potential functions and applications of G-quadruplexes in basic and applied biosciences.

核酸中富含鸟嘌呤（G）的序列可以组装成G四联体结构，该结构涉及通过环核苷酸连接的G四联体。几十年来，G-四链体的结构和拓扑多样性引起了人们的极大关注。最近的方法学进展已在体内和体外促进了G-四链体的鉴定和表征，并且具有更高的分辨率和吞吐量，这极大地扩展了我们目前对G四联体结构和功能的理解。对G-四链体的结构特性的积累的知识有助于设计和开发用于生物学应用的分子和化学工具库。这篇综述强调了这些令人兴奋的方法和发现如何为研究G-四链体在基础和应用生物科学中的潜在功能和应用打开了新的大门。