LAUSR

Abstract RNase, whose function was cleaving RNA in ssRNA, dsRNA or DNA-RNA hybrid chain, can be analyzed directly by fluorescence probe assisted with RNA. In this paper, we constructed a none-labeled RNase assay based on fluorescence probe with high sensitivity and specificity. Two TICT characterize probes (H2 and L2) exhibited strong luminescence when bound with RNA. Then RNase hydrolysis substrate RNA exposing probe into buffer and resulted in fluorescence quench, causing “OFF-ON-OFF” fluorescence switch. We successfully applied the assay to detect two kind of RNase (RNase A and RNase H) with the detection limit of 1.67 × 10−5 U/mL for RNase A and 1.06 × 10−4 U/mL for RNase H, respectively. Enzyme kinetics confirmed again the specific cleaving process. Moreover, this approach could also be used for the screening of RNase inhibitors. RNaseOUT was active against RNase A with the IC50 values of 0.88 U/mL, but not against RNase H.