Circular RNA (circRNA) is considered as a promising biomarker for various diseases owing to its unique functions and stable structure in biological circumstances. Nonetheless, homologous linear RNA always causes detection errors, posing a key challenge in effective circRNA assays for clinical applications. Herein, we present a novel method to directly analyze circRNA, eliminating homologous linear RNA interference. A dual-function circRNA-identifying hairpin (ih) probe is designed, which identifies target circRNA and initiates the subsequent hybridization chain reaction amplification. This method provides highly sensitive live-cell circRNA imaging capability and can directly monitor circRNA levels in biological samples, showing great promise for the analysis of low-abundant circRNA in clinical applications.

环状 RNA (circRNA) 因其独特的功能和在生物学环境中的稳定结构而被认为是各种疾病的有前途的生物标志物。尽管如此，同源线性 RNA 总是会导致检测错误，这对临床应用的有效 circRNA 检测提出了关键挑战。在此，我们提出了一种直接分析 circRNA 的新方法，消除了同源线性 RNA 干扰。设计了一种双功能circRNA识别发夹（ih）探针，识别目标circRNA并启动后续的杂交链反应扩增。该方法提供了高灵敏度的活细胞circRNA成像能力，可以直接监测生物样品中的circRNA水平，在临床应用中显示出低丰度circRNA分析的广阔前景。