G-quadruplexes (G4s) are fascinating non-canonical nucleic acid structures that attract broad attention due to their vital roles in gene expression and various applications. G4s exhibit high structural polymorphism and high resolution techniques (NMR, Crystallography) are often required to unambiguously determine G4 topology. Fast and handy techniques such as UV and CD provide interesting structural information. Here, we monitored the thermal denaturation profiles (TDPs) of various G4s at different wavelengths by UV, and confirmed that all G4 topologies (parallel, antiparallel and hybrid) exhibited hyperchromism at 243 nm and hypochromism at 295 nm. Furthermore, the absorption at 260 nm and 275 nm showed a remarkable topology-dependent behavior, and the hypochromism at 275 nm allows to discriminate parallel conformations from other G4 topologies. Therefore, this work provides a new inexpensive identification method for parallel G4 structures as well as a new perspective for the relationship between TDPs and G4 structures.

G-四链体（G4s）是令人着迷的非规范核酸结构，由于它们在基因表达和各种应用中的重要作用而备受关注。G4表现出高结构多态性，通常需要明确使用高分辨率技术（NMR，晶体学）来确定G4拓扑。快速便捷的技术（例如UV和CD）提供了有趣的结构信息。在这里，我们通过紫外线监测了各种G4在不同波长的热变性曲线（TDP），并确认所有G4拓扑（平行，反平行和混合）在243 nm处表现出增色现象，在295 nm处表现出变色现象。此外，在260 nm和275 nm处的吸收显示出显着的拓扑相关行为，并且在275 nm处的减色现象可将平行构象与其他G4拓扑区分开。