Circular RNAs (circRNAs) are a novel class of modified RNAs that are an abundant component of the epitranscriptome. Putative functions of circRNAs, include miRNA sequestration, RNA-binding protein scaffolding, mRNA trapping, and protein translation regulation. Deregulation in one or more of these roles has been linked to several types of cancer. One well-studied circRNA, ciRS-7, is believed to act as a miRNA- 7 sponge and inhibit its regulation of oncogenic receptors and tumor suppressor factors. Despite all the excitement around circRNAs, many of the recently discovered circRNAs remain poorly understood and progress has been extremely slow. An important reason is the lack of accessible tools to allow for the mechanistic study of individual circRNA. Recognizing this unmet need, a simple fluorogenic assay platform to detect circRNAs of interest in biochemical and cell lysate-based samples is proposed. In this Phase II project, the development of the ciRS-7 assays for biochemical and cell-based application will be finalized. Further, a robust standard operating procedure to streamline future custom circRNA development will be established. Lastly, assay benchmarks and distribution conditions for production scale-up will be determined. Upon completion, the circRNA sensor platform would find commercial applications in circRNA research, drug discovery, and biomarker development.