Terminal Deoxynucleotidyl Transferase, Recombinant, catalyzes the repetitive addition of mononucleotides to the terminal 3'-OH of a DNA initiator accompanied by the release of inorganic phosphate. Single-stranded DNA is preferred as an initiator. Polymerization is not template-dependent. The addition of 1mM Co(2+) (as CoCl(2)) in the reaction buffer allows the tailing of 3'-ends with varying degrees of efficiency.
