Halo-tag Mediated Self-labeling of Fluorescent Proteins to Molecular Beacons for Nucleic Acid Detection

We report here the generation of a fluorescent protein (FP)-based dual molecular beacon (MB) system for nucleic acid detection. Halo-tag mediated conjugation was used for the site-specific decoration of MBs with two different FP fusions, thereby enabling easy detection of target sequences by fluorescence resonance energy transfer or FRET. Enhanced intracellular delivery was demonstrated by simply tethering a well-known TAT peptide sequence to the N-terminus of the fusion proteins.