Real-time monitoring of double-stranded DNA cleavage using molecular beacons

Traditional methods to assay enzymatic cleavage of DNA are discontinuous, time-consuming and laborious. Here, we report a new approach for real-time monitoring of double-stranded DNA cleavage by restriction endonuclease based on nucleic acid ligation using molecular beacon. Upon cleavage of DNA, the cleavage product can be ligated by DNA ligase, which results in a fluorescence enhancement of the molecular beacon. This method permits real-time monitoring of DNA cleavage and makes it easy to characterize the activity of restriction enclonuclease and to study the cleavage reaction kinetics. (C) 2008 Elsevier B.V. All rights reserved.