TA cloning (also known as rapid cloning or T cloning) is a subcloning technique that avoids the use of restriction enzymes and is easier and quicker than traditional subcloning. 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. PCR products are usually amplified using Taq DNA polymerase which preferentially adds an adenine to the 3 end of the product. Such PCR amplified inserts are cloned into linearized vectors that have complementary 3 thymine overhangs.