Template-independent DNA polymerases

Abstract

Terminal deoxynucleotidyl transferase (TdT), is a template-independent DNA polymerase that catalyzes the incorporation of deoxynucleotides at the 3'-hydroxyl terminus of DNA, accompanied by the release of inorganic phosphate. TdT does not require a template and will not copy one. Reaction conditions and some applications are described in this unit, including cloning DNA fragments, labeling the 3' terminus of DNA with (32)P or nonradioactive tags, synthesizing model polydeoxynucleotide homopolymers, and detecting DNA damage and apoptotic cells.