The primary function of DNA ligase is to?

The primary function of DNA ligase is to reassemble DNA fragments produced by the use of restriction enzymes. The pieces are joined using a process called ligation, which uses the enzyme, DNA ligase which acts as a molecular 'stapler'.

The fragments are joined as follows:

- sticky-ended DNA fragments are created from two DNA sources using the same restriction enzyme.

- The DNA from the two sources is mixed and complementary ends allowed to form complementary base pairs. This process forming loose and temporary join by hydrogen bonding is called annealing.

- DNA ligase is then added to form a permanent link.