Polymerization-sensitive switch-on monomer for terminal transferase activity assay

Abstract

We herein describe a simple but efficient method for the determination of terminal transferase (TdT) activity, which relies on our finding that Fe(III)-quenched boron-dipyrromethene (BODIPY)-ATP is utilized as a switch-on monomer for polymerization and enables the facile synthesis of fluorescence oligo-nucleotides without additional, post-processing steps. As TdT carries out the synthesis of DNA by adding the monomers into growing chains, Fe(III) is displaced from BODIPY with the release of pyro-phosphate group, which consequently leads to the generation of highly fluorescent long oligonucleoti-des. With this strategy, we selectively detected the TdT activity with high sensitivity. In addition, its practical applicability was successfully demonstrated by determining TdT activities in human serum.