We present customized bioinformatic protocols for the identification and sequence characterization of semi-extractable RNAs, which are promising in understanding RNA-centric phase separation. Through a comprehensive bioinformatic analysis of multiple public datasets, we describe the unique sequence characteristics and interaction profiles of these RNAs, shedding light on their biological significance. Our findings provide a foundation for future investigations into the molecular mechanisms of RNA-mediated phase separations and their implications in RNA biology. The associated analysis code can be accessed at ( https://github.com/zengXchao/serna_mimb ).