TA cloning

The technique relies on the ability of adenine (A) and thymine (T) (complementary basepairs) on different DNA fragments to hybridize and, in the presence of ligase, become ligated together.

This polymerase lacks 3' to 5' proofreading activity and, with a high probability, adds a single, 3'-adenine overhang to each end of the PCR product.

It is best if the PCR primers have guanines at the 5' end as this maximizes probability of Taq DNA polymerase adding the terminal adenosine overhang.

[5] Manufacturers commonly sell TA Cloning "kits" with a wide range of prepared vectors that have already been linearized and tagged with an overhanging thymine.

Given that there is no need for restriction enzymes other than for generating the linearized vector, the procedure is much simpler and faster than traditional subcloning.