Thermo Scientific Terminal Deoxynucleotidyl Transferase (TdT) is a template-independent DNA polymerase that catalyzes the repetitive addition of deoxyribonucleotides to the 3'-OH of oligodeoxyribonucleotides and single-stranded and double-stranded DNA. TdT requires an oligonucleotide of at least three nucleotides to serve as a primer. With RNA as template TdT shows variable performance which strongly depends upon the tertiary structure of acceptor RNA 3'-end and the nature of nucleotide. Generally, it is lower than using DNA as a template.

Highlights

• Incorporates modified nucleotides (e.g., fluorescein-, biotin-, aminoallyl-labeled nucleotides)

Applications

• Production of synthetic homo- and heteropolymers
• Homopolymeric tailing of linear duplex DNA with any type of 3'-OH terminus
• Oligodeoxyribonucleotide and DNA labeling
• 5'-RACE (Rapid Amplification of cDNA Ends)
• In situ localization of apoptosis

Note

Due to the presence of CoCl_2, the TdT Reaction Buffer is incompatible with downstream applications. It is necessary to remove CoCl₂ from the reaction mixture by spin column or phenol/chloroform extraction and subsequent ethanol precipitation.